Here are some testing results:
bug66963-no-voltage.diff - hangs 5 of 5 times
bug66963-no-cg.diff - hangs 5 of 5 times
bug66963-no-gen2.diff - hangs 5 of 5 times

bug66963-no-ss.diff
hanged 4 times, then 2 normal boots, 2 hangs, 1 boot with Xorg delays, 1 boot
with garbage for Xorq (tty console was fine), 1 hang
Very inconsistent.

Also retried all 4 together:
Boots OK most of the time, though I get 2 hangs and 1 Xorg big delays in
between ~10 successful tries. Specially if reset is used instead of shutdown,
but sometimes it happens after shutdown too.

Will continue trying other combinations.