Can you use phylon 7 tractor beams and G8 experimental projectors in the same turn on the same ship, possibly slowing them down twice? Aka phylon 7 during your activation phase and then the G8 when the opposing ship conducts its maneuver.

Yes. You can also use multiple Q7's in the same turn to keep doing it. Do keep in mind 1) G-8's effect is temporary, so it's not actually decreasing the speed on their dial, just how far they move that one turn and 2) Q7's have a lower bound of speed 1.

Also worth noting that you can stack Konstantine in there as well. Not that you'd want to. But you could.

Thanks