Pity rewards for partial breach completion

So far only 1 breach mechanic (the classic "kill in circle" mechanic) gives partial rewards on completion. Both the fortress and hive can take a LONG time to clear and if if the NPC barely dies on the last second of the last wave you get NOTHING. We should at least get some proportion of the items or at least the graftblood from what we killed.

It really feels extremely risky and unfun to do it with any amount of juice if you don't have a build that is perfect at protecting her.