I found an example how it may be possible to use lvm names: NEWS.md says:
$ dracut --print-cmdline
rd.lvm.lv=debian/root rd.lvm.lv=debian/usr root=/dev/mapper/debian-root
The rd.lvm.lv parameters are only needed if you do not want to
activate all lv's. You may need to add rd.auto for autoassembly of all
lvm devices. See man dracut.cmdline(7) for details..
--
regards Thomas
