Nap length - cap?

G

Does anyone cap their toddlers naps now that they are on one nap? I can’t decide if after two hours I should wake him, or let him do 2.5 or even 3 sometimes. I do think if I let him have 3 hours he sleeps less hours at night but I’m not sure...thoughts?!

He always gets at least 10 hours a night but we are always aiming for more like 12 (7-7 situation).