Hello. I tried installing Ubuntu Touch with MultiROM and TWRP recovery without kexec-hardboot support enable, with the no kexec-workaround enable in the Recovery options, which resulted in a hard brick. I just want to warm people not to do this. CM12.1, CM13.1 and CM14 do not have the corresponding adapted kernel with kexec support, so don't use them as main ROM if you plan to install Ubuntu Touch, because the workaround available in the recovery will just cause a hard brick.
Installed developer build 218 its stuck at 1+ logo, and 219 build is throwing some error which states that multirom has been stopped to avoid file corruption.. On the move now will post details later if anyone wants them.