Hello,
It’s possible config full cache ONLY for Google bot?
My e-commerce load in 1-2 seconds, but Google search webmaster persist with warning LCP + 4sec and show many errors UX (SERP penalty).
Unique solution maybe, is set rule to Google bot (or knows bots) to load full cache.
In GT Metrix performance is 99%, the problem is a “little” Google. 
Any help is welcome!
Sorry for my English!