Wells is currently at 75 innings. What do we think his limit for the season is? 57 last year from the pen. I think you can take him to about 125 without feeling irresponsible or setting him up for a problem in 2023. Max of about 140.
~80 games left means he would be in line for 15-16 more starts.
You could place no limits at all on him and just let him do what he's gonna do and see what happens. You can limit him to 3 innings for the final 5 or so starts. You could skip him occasionally so he only makes 12 more starts over the remainder of the season. Could move him to the bullpen once he's close to where you want him to finish. Could shut him down for the final couple weeks.
Another option...is the option. Send him down for 3 weeks (21 days minimum) during the season. Those 3 weeks not accruing service time would mean he would finish the year with less than two years of service, rather than actually reaching two full years as he is on pace to do. So you then control him all the way through 2027 instead of only through 2026. He's not a guy I'd really think about manipulating for the purpose of service time, but if you're going to be doing some funky stuff anyways to limit his innings, I think its a good two-birds-one-stone solution.