As with many things, it will depend on the instructor, that being said....
It all depends what you are looking for. Since you stated "non-tech tune-up" then all of the various offerings would work for you, some would represent a better return on investment. From a "not going to tech" starting point, GUE Fundies would probably be a very expensive route to follow, though there is no arguing the skills would be solid. UTD Essentials of Rec, same deal but slightly cheaper (usually)
There is also the UTD Extreme Scuba makeover which focuses on the in-water skills, without going into some of the more Kool-Aid adjacent stuff, it is also a single day course.
RAID Performance Diver can be done in any config you are currently diving, the skills output would be similar (on paper) to GUE Fundies, though it would depend on the instructor again.
If you ditch the stipulation on "non-tech" then NAUI Intro to Tech is a good option, there are no actual deco dives on the course but the skills for tech diving translate well into safer, more enjoyable rec diving.
Honestly, if you don't need a card, I would approach some Tech instructors and explain what you are looking for and accomplish the same with mentoring. No cert fees or other agency BS and you can work out a bespoke curriculum based on your needs. It will almost always work out cheaper and more targeted. Just remember that if you do get the tech bug, most of these courses act as prerequisite courses for further training so you will need to get the card if you plan to progress further.