Things I've found useful on a similar journey this year that may be useful (I've been semi-full time on a T560 since Feb - and likely aged at least 3 years in this time)
Start again from scratch, literally everything you can adjust or change should be looked at, make a list of *everything* you can adjust / measure / check / change and write it out...
Then do not heat the room as working in a hot space can test your patience more in my experience (not sure how appropriate this is in florida! but maybe do all the calibration with the AC running
....then do all the things you can, and importantly talk it through *out loud* the whole time - rubber ducking your set-up as you're a programmer - this is massively transferable imo, I do this and it defo helps.
At least twice I've been caught out with really basic things I _thought_ were correct but weren't, there's a chance this could be the case for you so worth ruling it out... and be super picky and perfectionist with everything you can, tiny tiny adjustments matter.
Audio wise, use a file that has been mastered for vinyl if you can, or at least one shouldn't cause you any issues - I've chased issues for a day or two that end up being source material - best to rule this out.
Make sure you measure your groove depth, I've found minor adjustments here can have massive impact to the levels you can cut at... for my setup about 70μm seems to be best, your results may vary, this is worth experimentation.
Rake angle is also another huge factor in end loudness / clarity / background noise... again some experimentation here will likely yield results.
Goes without saying but if you're changing a parameter then do this one parameter at a time... if you have a hunch or get some better results it's the only way you'll have confidence.
Essentially read the spinnertown blog and do all the things, but also with the knowledge that your results may vary for some things.
Might be worth paying to have your cutting head EQ mapped just to know for sure you're working with a solid EQ - that said, I didn't have bad results following the guide Matt shared, but sometimes knowing for sure that someone who really knows what they are doing has been involved will at least reduce your possible areas of concern by one.
If there's any way you can get someone else locally who knows what they are doing to help then I found, once I'd been through everything myself and had another more experienced set of eyes on things, that my confidence grew and I'm usually able to have an idea of what issues might be - if this can only be done remotely on a video call or something, think about having an extra webcam for closeups - make it easier for someone to help you if you can.
If you've done all of this, and still aren't getting decent sounding cuts I'd be surprised - as long as there isn't some underlying issue with the cutting head, then it's hopefully just a case of back-to-basics and one more weekend between you and decent cuts!