Do not know if this is interesting anybody...
Just a simple thing: I changed QuickCart to use YAML CSS Framework.
My idea: 1 Template, 2 Systems -> crossover Site, no change for user...Easy updates on BOTH sites, seems like working. Same Security as 2 Systems alone.
Missing: a phpwcms output of Navigation, just hardcoded in the Moment. IE Clearing in QC Will give it a try in the next future.
This should (!) work with xt:commerce as well.
Early BETA *g* but needed to be productive this week. QCart is not hooked in phpwcms Navigation at this moment, but this is just a link. Backlinks QC ->phpwcms are running.
pkpwcms: http://ukw-tagung.com
QuickCart: http://ukw-tagung.com/qc
phwcms css Files also available in QC, QC cuttet off for Body statements. Any Template change goes through both systems as well imediatly.
IE checks will be LAST thing I do, I left out the IE clearing in QC Template, Charset is not defined yet in QC, minor problems range also behind

Motivation: This system was running productive last year with JS implementation, some 3% of super secure users did not come through, JS cuttet off

Leaving for fine tuning.
Principally this method is also possible without yaml, but takes 2 systems browsercheck.
When ready likely sharing this with this great community, if needed by anybody.
greetz Jürgen