Forgot to mention some errors... but not related to UEFI changes, I think...
On bare-metal the installation failed 2 or 3 times showing some python errors on anaconda installer.
I think anaconda is at fault for that. IIRC the installation continued after deleting the software RAID using another partition manager.
IIRC, these anaconda python errors also happened on v6.x, so UEFI changes are not the issue.
Also, once got a 4m[terminated] message and a sudden reboot when anaconda was about to install packages.
The next installation attempt succeded. Once at the login prompt I could ping to external sites, until shorewall came into play and logger errors appeared on CLI, losing Internet connection:
I think NetworManager has something to do with it.