Since you are making an analogue of PGF, it would be great to add one more feature to completely abandon PGF.
One Click Sign Up - Sign up for a group directly by clicking on it, instead of selecting it first, then clicking sign up.

This would indeed be good but there is also a WA doing just that :
https://wago.io/6-GG3RMcC/

The only 2 things I sometimes miss from PGF are the groups that refused you been color coded in red and the possibility of choosing raid difficulty and min/max numbers of bosses dead. :)