This sounds incredibly legit, but question: Could you not gain a shit ton of momentum sailing directly with the wind in a regular boat, then drop your sails and steer into the direction of it to maintain some amount of velocity for an amount of time? Feels like the same principle could be applied here, especially because they would swap between photon momentum and gravitational momentum
Counter-argument, this is all correct, but when the application is against shopping mall criminals it will work well enough. Not talking masterminds here