Well I dont have any sites using perimeterx so cant really help.
Only other thing I can think of is using Pupeteer and use some plugins like Trace and Spooftimezone
Also try Bromite browser (chrome fork) - originally made to provide privacy to android webview but carries over all the features to the general browser including awesome anti-fingerprint
Well for my specific site i was able to somewhat bypass the px ratelimitation. Atleast to be able to do things. It does still interest me how px can do this. Anyway thanks for the help.