ABS pipe is not supposed to bottom out during dry fit in fittings. However, if you dry fit a few times (for example to work out a complex geometry) or wiggle the pipe in the fitting a bit it seems like the joint often gets loose enough to actually bottom out, or nearly so. The fittings are tapered and the tolerances are supposed to be pretty tight for the solvent weld to do its thing... in theory at least -- in practice I am wondering if there is much consequence to a pipe bottoming out in a fitting during dry fit. Is the concern that the joint will fail OVER TIME or will fail immediately (upon test)? If a rough-in is water tested with water through the roof and it PASSES is that proof enough that one escaped any consequence of bottoming out or is it somehow more insidious than that and it will fail, perhaps, some time later?