No idea I'm not a game design expert I just think it's it a bit weird that you can only use one technique to farm at a time espically. I can see ressons to keep them separate though  or even remove the puratory entire since there are more up-grades for the combat so I would ask more people before doing anything first. I originally just wanted to know if that was inttended or not sorry.

Okay I managed to collect them, but there seems to be a minor bug. Sometimes the souls aren't collected when I mouse over them.