Hello MWS'ers!
Update. I managed to remove the safety and now everything is in order again.
I received the Guns Modify EVO drop-in steel trigger box set today and just installed it tonight. After reinstalling my safety, I simply can't flick it to auto -- it won't budge past semi. This poses two problems: 1) I can't select full auto, and 2) I can't uninstall the safety again. Does anyone know how to get around this? It's a bit of an issue, as I need to remove the trigger box again to fix yet another issue, namely that the ZET plate seems to be misaligned ever so slightly with the bolt catch which causes the ZET plate to roll off of the bolt catch and then jam the catch (during firing). I used the original ZET plate, but the GM kit comes with its own -- so that might be the issue here. In any case, if someone has any tricks up their sleeve, do let me know.