How properly install w3tc in wp network – no instructions found?

I’ve being using successfully for a couple of months W3TC in a single wp site installation. As soon as I moved into a wp multisite installation problems begun on my second site so I decided to uninstall the plugin to installed it again.
I have been searching for two days instructions on the proper way to install this plugin on a 4.2 multisite subdomain + WordPress MU Domain Mapping on a shared host (apache) but I cannot find anything at all.
I read that:
1/ installation must be per site
2/ all sites should have the same settings to avoid .htaccess conflicts
I AGREE WITH THAT BUT:
1/ In the particular case of this plugin, it seems that I only can activate this plugin in the network. I cannot activate this plugin separately in a single site as the rest of the plugins and I dont know if this is norma lor my installation is corrupted.
2/ Networked activated (as the only possibility) what should I do to follow Frederik recommendations (https://www.ads-software.com/support/topic/plugin-w3-total-cache-multisite-installation?replies=4) – activated on a per site basis
A/ should I forget any settings on super admin w3tc dashboard? Apart from uncheking ?Use single network configuration file for all sites”
B/ Considering that all sites should have the same settings to avoid .htaccess conflicts, I must configure the general options on the super admin w3tc dashboard and the particular options of every single site on their own w3tc dashboard ? (I just only see sitemap URL or uncheking ?cache request only for xxxx.com site address” as particular ones)
Any information will be appreciated.
Thanks
Fernando