The xkbdata package doesn't get installed by default with modular X currently.
This prevents ctrl-alt-fN from working to switch VTs.
The X server probably needs a Requires line for it.
Fixed in latest modular Xorg build. Note however, that even with xkbdata
installed, xkb only works if the X server is started from a system with
a read-write mounted /var. That will probably change in the future though
with popen() or somesuch.