it appears to violate conventional physics and the law of conservation of momentum;
No, it does not, otherwise it would not work.
A theoretical physicist, an applied physicist, and an engineer walk into a bar.
The engineer says, "Thanks barkeep, may I have another?"
The bartender bets the three that he can serve them beer at FTL speeds.
The theoretical physicist says, "Preposterous! That would violate all sorts of fundamental laws including causality!"
The applied physicist says, "If it works, it doesn't matter what your theory says!"