Dell enterprise series of desktops (Optiplex and Precision) are upgradeable with off the shelf parts. The CPU, RAM, SSD, GPU, Network cards, etc. The same way a regular motherboard from any manufacturer does.
For example an Intel Core 8th gen system would POST with any 8th Gen CPU, any type of DDR4 ram and would boot from any disk. You cannot upgrade an 8th gen to a 12th or 14th gen from any brand, the only proprietary properties of these systems are the case or motherboard form factor and the power connectors.
Do you have a spare set up where you can boot up from that same SSD? Literally any laptop would work plug and play and that would rule out the possibility of it being the motherboard on the OP.
I know a guy fitted for the job. He's well versed in MS-DOS, Win 3.1, 3.11 etc. Hell, he's even fluent in German, but he's due a hip and knee replacement this month...
Yeah unfortunately that Custom ROM scene is dying out, I see that plenty of older phones are still supported (e.g. Galaxy Note 3, Samsung S5, kind of all Xiaomis) but newer phones are just a handful of models which its bootloader can be unlocked, and then some of these have support for Magisk and TWRP but sadly no custom ROMs.
Edit: still the ability to root these and unbloat them is better than nothing.
Imagine my mixed emotions when I’ve been doing ‘ls -la’ since I remember and watch someone do ‘ls -al’.