Every fall, IT admins brace themselves for the same ritual: a new major macOS release lands, and suddenly there's a fleet-wide scramble to get every Mac updated before deadlines, security requirements, or simple peace of mind demand it. Major upgrades are a different beast than routine point releases — bigger downloads, longer install times, more user disruption, and a lot more that can go wrong if it's not planned out.

The good news: Proximos will fully support macOS 27 Golden Gate, and with Major Mode, you can have your entire enforcement plan configured and ready to go before Golden Gate is even released. Here's how it works, and how to set your organization up for a smooth upgrade cycle.

Set & forget

Major Mode lets you configure enforcement well ahead of time. You can:

• Set a specific enforcement date for the date Proximos will require the upgrade to happen — even if the specified date is configured before the release of Golden Gate.
• Scope settings to specific groups or individual Macs in your MDM, so you can roll the upgrade out by department, by lab, or on whatever staggered schedule fits your organization — rather than forcing everyone through the same door at once.

Once Golden Gate is released, Proximos handles the rest: detecting the new installer, downloading it, and tracking the countdown to your enforcement date without any additional admin intervention.

Automatic Download — No Manual Staging Required

Major upgrade installers are large. Golden Gate's full installer will weigh in at roughly 12 GB, and manually staging that across a fleet is a headache nobody wants. Proximos handles this natively using Apple's own softwareupdate tool under the hood — no third-party download tooling, no custom scripting required. Once a target Mac is enrolled and within reach of your enforcement window, Proximos checks for the installer, and if it isn't already sitting in /Applications, quietly fetches it in the background from Apple while notifying the user that a download is in progress.

A Friendly User Countdown, No Surprises

Nobody likes being ambushed by a forced restart in the middle of their workday. Proximos gives users fair warning through a daily countdown of notifications in the 30 days leading up to your enforcement date, appearing on these milestone days:

30 · 25 · 20 · 15 · 10 · 5 · 4 · 3 · 2 · 1

These are lightweight, dismissible notification banners — informational only. Proximos does not open Nudge or force any action during this countdown window; it simply keeps users informed so the eventual enforcement isn't a surprise. Once the enforcement date arrives, Proximos launches Nudge to guide the user through completing the upgrade.

Here's a simplified look at how Major Mode makes that determination behind the scenes:

Major Mode Logic Flowchart

Major Engine triggered
        │
        ▼
Is the Mac already on or past the target major version?
        │ Yes → done, hand off to Minor Mode for point updates
        │ No
        ▼
Resolve & download the Golden Gate installer (if not already present)
        │
        ▼
Compare today's date to your configured enforcement date
        │
        ├── 30/25/20/15/10/5/4/3/2/1 days out → send countdown notification
        │
        └── Enforcement date reached → launch Nudge to enforce the upgrade

Perform silent macOS Golden Gate upgrades

For labs, shared workstations, kiosks, or any unattended Mac where you can't rely on a user to click through Nudge, Proximos also supports a fully automated, silent upgrade path using startosinstall instead of Nudge-driven enforcement.

You'll find the script — startosinstall Major Enforce.sh — bundled with Proximos:

Downloaded Proximos app DMG → Extras → Advanced Scripts → MDM Tools

A few things worth knowing about this script:

• Silent, unattended installs. Configure it with a local admin password for the target Mac, and it can drive a completely silent, automated major upgrade — ideal for lab machines, shared devices, or anything sitting unattended overnight.
• Optional heads-up for users. Enable an optional pop-up notice that gives the logged-in user a five-minute countdown before the install begins, so it's not a total surprise if someone happens to be at the machine.
• Trigger it based on enforcement status. The script is designed to be run from your MDM based on an extension attribute reporting "Past Due" status, so you can build a workflow where Macs that have crossed the Proximos enforcement date are automatically upgraded — no manual follow-up needed.
• Secure Token matters. For the smoothest results, make sure the local admin account whose credentials you supply to the script has a Secure Token granted. This avoids authorization hiccups during the startosinstall process.

Combined with Major Mode's enforcement date and countdown notifications, this gives you a genuinely hands-off path to getting stubborn or unattended Macs onto Golden Gate — without chasing anyone down.

Customize the Nudge window for your institution

Nudge's messaging can be fully customized for the Major upgrade experience — separate from your minor update text. That means you can tailor the language, branding, and urgency of the enforcement screen to match your institution's tone, compliance requirements, or internal policy language, so users see messaging that feels like it's coming from your IT team, not a generic tool.

Why We Recommend Skipping Dual DDM + Proximos for Major Upgrades

Declarative Device Management (DDM) has become a great option for many update workflows — and it coexists well with Proximos Minor Mode. But for major upgrades, we recommend running Major Mode on its own, without DDM in the mix.

The core issue is timing. DDM enforces updates based on a set number of days after Apple's release date — it doesn't give you a way to target a specific, admin-chosen enforcement date the way Proximos Major Mode does. If both are active, there's a real risk that DDM's own schedule triggers the upgrade earlier than (or in conflict with) the enforcement date you've carefully planned in Proximos. For a disruptive, fleet-wide event like a major OS upgrade, you want one clear source of truth for when it happens — and that should be your Proximos enforcement date, not DDM's default timing.

The Bottom Line

Major macOS upgrades don't have to mean weeks of manual staging, awkward DDM timing conflicts, or hunting down the last few unattended lab Macs by hand. With Proximos Major Mode, you can:

• Configure your Golden Gate enforcement date today, ahead of release
• Let Proximos handle the ~12 GB download automatically once it's available
• Give users a fair, predictable countdown instead of a surprise
• Roll out by group or individual Mac on your own schedule
• Go fully silent and unattended where it makes sense, with startosinstall Major Enforce.sh
• Keep DDM doing what it does best for minor updates, and let Major Mode own the big upgrade

macOS Golden Gate is coming — and with Proximos, your fleet can be ready for it well before it arrives.

Questions about setting up Major Mode for your environment? Reach out to our team — we're happy to help you plan your Golden Gate rollout.