munki VS macOSLAPS

In the non-MDM tool space, look into Munki https://www.munki.org/munki/

this experience is an indication that the opco didn't hire the right expertise. If the numbers you quoted ie 30k desktops, 50k total were not macs, it's clear that the org didn't have the kind of mac experience needed to manage a a new org with all macs.

It's entirely possible for administration of macs.

Start networking/asking around with places like Disney or Pixar, etc which have a large amount of graphic artists using macs. For example, from Disney https://github.com/munki/munki gets you to a certain point.

Other tools like Kandji (lightweight) and the 900 lb gorilla in the industry Jamf gets you the other management / administration bits needed

If this opco that you referred to never got a Jamf rep to work with them and to try out their (yes, very expensive) products, then this is mostly inexperience with the mac ecosystem.

There's a decent open source option: https://github.com/munki/munki

I got to use it at work at Meta (as end user), and it seemed to work quite well. They delivered Android SDKs/IDEs and a bunch of other things that I'd personally install through Brew with Munki.

Munki is not an MDM and I recently learned there's this project called Installomator that might help.

Or Munki

This is a feature of munki called default manifest resolution. Though I prefer to avoid this and explicitly set the client identifier for all devices.

another option is munki https://github.com/munki/munki, for the software update part,

LAPS isn't natively supported but once again there's a third-party solution

As others have mentioned, a second account with admin privileges might be your best bet. If you're going to go that route, you may want to implement macoslaps along with that. Macoslaps randomizes the local admin password which comes in handy if you need to give the password to someone. It used to be only for Active Directory joined Macs but now can be used without an active directory (via MDM). Here's the link for more info: This goes on the clients - https://github.com/joshua-d-miller/macOSLAPS

We use MacOSLAPS on our Mac clients to randomize the admin password on those machines: https://github.com/joshua-d-miller/macOSLAPS

And that implementation is why when I set this up at $oldJob I set the RemovePassChars key to all ambiguous characters I had run into on the Microsoft product.

I believe setting something like macOSLAPS up will also resolve the issue since the automatically created local account would authenticate and update it's password silently.

There are a variety of alternatives, such as https://github.com/joshua-d-miller/macOSLAPS