1) What is possibly going on?
In the past I found some stalling trying to return from MM to an already active MekHQ session. I suspect the problem was in memory management (it can be a serious memory hog with large/complex maps, fire/smoke, etc. and long turn-count games) from running multiple sequential scenarios. I've taken a number of steps over the years which have seemed to minimize the issue. The first is to use the Java configuration file to allocate more RAM to both MM and MekHQ. The second is to always save and close MekHQ after completing a scenario. The latter frees up all memory otherwise allocated to the Java session, and reloading tends to fix a few other issues such as tactical support/leadership reinforcements showing up in multiple pending scenarios e.g. deploying supporting infantry through StratCon for the next scenario tries to deploy them to the other two, including the one that is space combat. Another issues it solves is being unable to unload external ordnance like bombs and rocket launchers from salvaged aircraft.
2) Why is MM still thinking the stricken crews/mechwarriors are still valid targets (thus need to be hit to forced withdrawal or destroyed)
They are still valid units. Whether you consider them valid targets or not, is another matter. Ejected MechWarriors and vehicle crews should be flagged 'crippled' by default and Princess should be withdrawing them to the designated forced withdrawal edge without needing to shoot at them. The only time where they won't, would be blocking terrain, conditions which reduce MP e.g. they tend to sit and spin in the dark, or the Princess settings have turned off withdrawal.
Well before the game gets to that point, though, I /kick the OpFor players and replace them with new settings that has them withdrawing off the map in a more or less organized fashion, depending on situation. For example, under a Pirate Hunting contract I have the OpFor break when they've taking only 25% losses by BV or lost a particularly valuable Mech - pirates aren't known for fighting it out as there isn't any benefit to them. At that point I /kick them and set the destination edge to "Nearest", as they're not coordinated enough to withdraw properly. Contrast that to, say Federated Commonwealth forces where they stick it out until around 50% losses or the situation is judged untenable, at which point they stage a fighting withdrawal back to their home edge.
I don't issue the /victory or /defeat commands to end the scenario even if the MekHQ defined conditions are met. Things get played out, allowing for more opportunity to claim salvage and/or prisoners and more time to withdraw friendly units to safety. The command gets issued when the end result is more or less fixed i.e. there's little to no chance of crippling/killing units before they can leave, or they cannot reasonably leave before that happens.
