You just pull thru the head. When you get to the throat you can tension from there as well.
The only Head RB Racket I've strung was a Liquidmetal. One of my clients is supposed to drop off some Head Scorpions which have the channels in the handle. I don't think you need a Brake to tension those.
Machines: Gamma 6004 2-point w/ Wise 2086 & Babolat Sensor Dual