I will try to collect the most issues/ bugs here with the mod
Bugs:
Operation Spartacus doesn't work. The reason for that is the event to trigger the slave uprising doesn't trigger.
Power Armour: You can't research the first few techs since the mod wasn't updated to research the basic power armour tech. If you want those techs you need to use the console.

'Features':
Purist:
Lawless Wasteland: This mechanic was with La Res added. When you reach 30 Resistance it switches to your 'puppet' the Lawless wasteland. You can restore control with Comand Power on the state menu. There are many custom law to still get the some resources out of this land but until a real update comes out you will need to get through the pain.
Caps: The purist don't use caps (as do the reformers till they conquer New Reno). In fact Caps are disabled meaning you can't upgrade your agency with them.

Reformers:
Instant War Caesar Legion: This is a result of the Legion focus To the West which instantly declares War on you meaning you don't get the peace time you need.
Leaving your Faction: Honestly I am not entirely sure this is still relevant but you the Mormons or Texas might leave your faction because of their csutom focus tree.

Let me know if I might have missed anything. I will try to update thiss list as much as I can.