The APC is fine at 190F. Make sure you use an insulated vessel that protects your countertop, minimizes water loss and with a cover that keeps your APC from being bathed in hot moisture evaporating off the surface. Never a good thing for electronics.
But 190F is way too hot for ribs.
If you want to SV them, lightly salt them and leave them for a few hours to dry brine (helps retain moisture). SV at 145F for 24 hours. If you’re vacuum sealing you may want to wrap the bone ends with some HD foil to prevent bag punctures from sharp bone edges. Then remove them from the bags, discard the salty purge, apply a salt free rib rub to the wet ribs, and smoke them for 1-2 hours at 200-225F. The moist surface helps with smoke adhesion. At this point you can glaze them with BBQ sauce and quickly grill or broil to brown and set the glaze. Or you can wrap and freeze them, then thaw them out when you want to eat them, glaze them and grill/broil to heat them up and set the glaze.
When I first got my APC I tried ribs many different ways to dial it in. If I rubbed and smoked first, then SV’d, I got a bland rib that lost a lot of the smoke and rub flavours to the purge. Smoking after SV’ing was the way to go.
That said, although SV’ing will give you a fine tasty rib, it’s different than a traditional 225F 3-2-1 smoked rib (3 hour smoke, 2 hour wrapped, 1 hour glazed) and it misses some of the texture and complexity of flavours you get with a rib smoked low and slow. BTW, when wrapping ribs for the 2 hour braise part, too many people seal the ribs up tight in foil. You want a loose wrap (just folded over) so some moisture can escape and you retain more of the bark texture.