> My university now requires the use of a school-managed VPN on personal devices to access most student services outside campus.

> They do not and have never offered school-supplied laptops like companies usually do for secure connections.

One solution here, although you may not like it, is to obtain a second "personal device" and dedicate it to use with the school network. I.e., supply your own "school-supplied laptop" that is only used to access the school, and never used for any personal use.

Note -- this does not mean you have to buy a new laptop/desktop, a used/second-hand system that is a few years behind cutting edge is likely still more than enough for school use, while being significantly less expensive than a brand new system.