So the scenario that I'm wondering about (not trying to be difficult, just curious)... Runner at 2nd and 3rd... hit to SS and a slow batter-runner.... SS tags 2nd who was advancing unforced and the runner at 3rd had a nice lead and is fast. The runner from third crosses home before the forced out at 1st...
The run doesn't count.
No run may score on an inning-ending play in which the third out is a force out or on the batter before he reaches first base. Put in other words, force outs count before runs are scored.
You can read about "fourth out" to understand the logic. https://en.wikipedia.org/wiki/Fourth_out
In a situation where a third "non-forced" out is made AFTER a runner crosses home plate, the defense team can try a fourth "forced" out to prevent the run from scoring.
So any forced out counts before a run is scored.