While we're looking for ways to make the APC's transport ability more relevant, let's let the phase tank do it too.
"Standing still" is a dubious term for vehicles; it can be hard to bring a vehicle to a complete standstill (though easier for tracked ones) and if you have the FPS/velocity display enabled you may have noticed that even if you have managed to get a vehicle to stop completely, if it's on a slope it still reports as moving at something like 0.08m/s.
Something that could be done is something similar to how the Engineer's mine detection works; give infantry a script that makes it so if they're within a certain distance of a Phase Tank, the Phase Tank gets a radar marker temporarily attached to it. Since Volkov is part machine, maybe not being so easily fooled by tricks of the light could be another niche for him, creating an unusual dynamic where he's good at sniffing out phases but is also the easiest infantry for phases to kill due to tracking. Or alternatively, it could be a thing for the Shock Trooper for similar reasons to why the Tesla Tank jams radar?