Compatible Caching Solutions
So, to clarify with wpForo, due to the caching mechanisms built in to the plugin I can whitelist WPForo from all caching plugins (AutoOptimize, W3TC, LSCache, Redis, etc.) on the front-end?
I ask because the first time to byte is horrendous on the main forum/community pages. The server all the way down to WordPress is optimized heavily and has near perfect scores (GT Metrix, PageSpeed, Pingdom, WebpageSpeedTest, etc.) except for those heavy forum pages. Almost three seconds on every load waiting... then 2 more seconds to execute tons of js requests..
I have spend a lot of time testing various caching with wpForo. Because i have a small hosting plan and a lot of sites.
With most caching plugins you have to exclude the wpForo page. They say WP Rocket works right but it is a commercial plugin and i can't test BUT i highly doubt it works 100% right with wpForo.
Autooptimize is not a caching plugin (as you say).
So what works ? For me, i could get caching to work with WP Super Cache in PHP mode (not in expert mod_rewrite mode) almost 99% with wpForo. There are some things that are not updated immediately (like # of views and widget sidebar new topics/posts) but i don't care. And those problems are for VISITORS and not logged users. Also those problems can be improved by setting a low TTL (time to live) for caching, so caching is cleared every xxx minutes instead of for example once per day.
I think wpForo last 1-2 versions made the plugin more compatible with std Wordpress caching mechanisms, so it works better with WP Super cache (a caching plugin that i do not like).
LiteSpeed caching plugin, while it seems to work with all webservers, it really shines in you are also on a Litespeed webserver. Otherwise ....
W3TC has always been a red flag for me, it only creates problems and nothing else. But if it works for you ...
Apparently you have to test what works in a particular setup, there is no other way.
A friend of mine uses W3TC with object/page caching and Redis and he is more than happy. But not with a Forum.