Bubble Drive...

Now that bubble fusion appears to be panning out, as least as a
neutron source, can anyone design a "bubble drive" to take direct
advantage of it - beyond the obvious of getting it beyond energy
break-even and using it to power other forms of rocketry?

I'm not sure what the current ratio of energy input to output on the
neutrons is currently, but the researchers seemed confident that they
could improve it. If it could get anywhere close to 1:1 it might be
useful as a means of generating neutrons as reaction mass. E.g. you
might cause bubble fusion in a thin layer on one side of a wide and
thick lead shield. Use that to spin up a tether system that is used
to launch ships via momentum transfer.

Anyhow - better ideas?