I use defer on all banners from adsense <script defer src=
Do not show banners on main page or banner Body Right/Left...All the rest is usable and is not causing to much delay.
Merge internal CSS style sheets into one enabled
Minify/optimize merged CSS style sheet disabled - Minify slows me down
Merge internal JS scripts into one enabled
Minify/optimize merged JS scripts disabled because some plugins do not work correct anymore.
I use cache plugin and webp plugin for images and no use of lazyload because it slows me down with 15%
Opcache for php is enabled...
No use of memcache / memcached / Apc or others
Maybe some small other changes in code witch i don't remember what exactly (or keep them to myself
....)
I also changed categories on home to grid view but don't know if that was a difference in speed.(not tested)
Note: That i am on a private dedicated server with 24 cores and 16gb ram.
Maybe all this is not having effect on your website but mine is doing great with it.....
Good luck