Nike M5E1 solid trust curve is too steep

[Codelet]

When Nike M5E1 burns out its trust drops to 0 almost immediately. Trying to make something like Aerobee 170. Starting both engines from the pad but, as soon as M5E1 burns out, the Aerobee engine (AJ version) cuts off because of too fast acceleration drop and thus ullage issues if I understand it right.
If I take something heavier like sparrowbee and replace solid with M5E1 it would work though.
Other solids seems to have nice smooth burn out curve which allows to keep ullage just fine.