This may not be all that helpful, but if your willing to learn (and possibly fry your controller) you may have a makerspace near where you live. If so, they would most likely have a soldering setup that you could use for a small fee.

Or heck, my local Library has a tool checkout system. Check with your local library (the bigger the better) as there's a non-zero chance that they could loan you one.

Do you know where to get drop-in replacement Hall effect sticks for a DualShock 4 or DualSense? (Maybe they're easy to find now; I haven't looked in a while.) I have a soldering iron and would probably buy a set.

Edit:

I just learned that TMR (tunneling magnetoresistance) sticks now exist, and are easier to retrofit in Sony controllers, apparently because they use less power and therefore don't need an additional circuit board. Thanks for renewing my interest.