Captain Future's enemy had one of those.
"quantum vacuum virtual plasma"
Star Trek science alert.
The last time I saw that "microwave-based reactionless drive", the prétendu thrust was conveniently plotted without error bars. That was also when it appeared in NewScientist and I decided to not renew my subscription.
The system uses microwave energy reflected around a specially designed chamber to produce thrust.
The last time I thought about it, it seemed evident to me that the force towards the "front" would exactly equal the force towards the "back". So turn the engine around and it will still work the same ... uh ... wait ...
Additionally, in case it magically works, then we have the good old Aether and an absolute reference system back. So no, it won't work. Fracking self-licking icecream drive.