what is your opinion on this plugin? {screenshot attached}
Most likely not, as forums are dynamic and the content is always changing, so if anything is cached at a server level you will have threads and forums not updating properly.
if you are using apache and this offer change it to litespeed,Of course, that's the right thing to do,LiteSpeed and Apache are both Http server software , but LiteSpeed is much faster
Yes, it depends if the caching is automatically enabled or if it requires a plugin (and is only aimed at WordPress). If it's only changing the HTTP server software then that's fine, but you probably won't want any server-level caching enabled.