There is no document detailing what doesn’t work in webclient however I think that you can ask specific questions in the community.

Hi Atheeq,

I Referred the differences mentioned in the previous post as well. If you require more updated changes introduced with FSM 6 release you should refer the Release notes. 
Hope you can find all differences and similarities referring to the attached document. I thought not to extract from the doc but to attach the doc for you to have a better informative source.
Hope this helps. :)

Best Regards,
Tharindu