I've given up searching for a premade repair shop POS as they're all built for electronics or car repair businesses and even though I could probably manage using them, the doofus sitting at the front desk wouldn't. Would anyone be interested or has any info on where to turn?
Any help would be appreciated. Thanks!

What exactly do you need? If you google "custom point of sale software" there are a lot of hits. POS is used in every business so why not go store to store asking what they use and who they rent from.

We've tried that. Lightspeed is actually one of the first results if you search custom POS and they claim they provide software to jewelry and watch repair businesses.
We signed up for a trial and did a screenshare with a rep to show us "how we can customize it"
Turns out there's nothing you can actually customize. For a few things the rep had workarounds for how we wanted the POS to work, "well you can do this like this, you can do that if you do it this way" until we got to something they couldn't do.

A lot of others also offered us to try computer, phone, or auto repair software, but it lacks the layouts that we need and they weren't willing to change it for us.

Sounds like you want something pretty specific.

Maybe lay out the requirements and nice to haves.

At this point all you've said is you want something semi generic that is customizable to your liking, and sounds like you haven't had much luck getting it.

You will likely need to hire someone for custom software. POS front ends are not to terribly hard to write, it's just interfacing with the hardware which might be a pain.

Finally found a company that claims to offer most of what we need and agreed to program in additional features free of charge as these features will improve their POS for future customers. Going to have a screen share with them tomorrow. I'm hoping it goes well and it's not just all talk.