Google webmaster tools test fails the Mobile Speed test. One item Google says needs fixing is: "Enable compression".
I have installed Optimizer 2.0 on a DNN 8.04 site. I have enabled compression on the module settings and have a modern responsive skin.
Does the Optimizer relate to this test?
I found the following entry in a DNN article: Note: if you enable IIS dynamic compression be sure to disable DotNetNuke compression (host->host settings screen)
Gzip compression is no longer a configurable DNN Host setting in 7.4.x, but, does Revindex Optimizer conflict with IIS Static or Dynamic compression?
The Google message has to do with your DNN/IIS site not being compressed as you found out. The Optimizer will work with either compression enabled/disabled.
Any concerns with the use of the Revindex Optimizer and a CDN such as CloudFlare?
No concern. It should work fine.