I don’t think horse will do better for BF with constant contact. BF will probably be too heavy on the reins just because he lacks skills horse is used to. Plus if he already is hanging on the reins constantly, horse never gets relief, won’t notice the pull if he wants to spook or go faster.
A suggestion is to put horse in a mechanical hackamore, with nothing in his mouth to bug him. Then teach BF to use outside leg WITH outside rein, to get horse to fake a neck rein response when asked to turn. All our horses can do the fake neck rein thing, fools everyone. I would also have BF use BOTH HANDS on the reins, which will keep his body balanced and not leading with one shoulder or weighting one hip. That is hard on a horse being ridden for distance or over a couple hours time out on the trails.
The mechanical hackamore should not need constant contact, but will give some leverage pressure if horse gets very strong to slow or stop. I use a mechanical hackamore for little kids who have poor balance, might be hanging on the reins, but NEED to be able to stop the bigger and stronger horse. Kid MUST win every time! Person safety ALWAYS trumps horse comfort for that moment of stopping!! Horse has to stay under kid’s/rider control. With no mouthpiece, horse mouth is not getting pulled or ripped on by rein leverage. Leverage with curb strap, still keeps horse controllable for the rookie riders.
I would suggest a mechanical hackamore like this model, with addition of a fleece noseband over the rubber part. Makes it quite comfortable to the horse nose. I would remove that chain curbstrap, probably try a leather one if your horse is not used to leverage bits. Some horses can just work better in chain curbs than they do in leather. You will need to ride and see how he responds to make your choice. He sounds like a bigger horse, so you use the curb strap or chain that works for him, to get him stopped.
http://www.jeffersequine.com/rubber-nose-hackamore/camid/EQU/cp/A8-D3/cn/1101511/
I would NOT recommend the English Mechanical Hackamore, because I have seen horses run right thru them. No stopping power, even with the chain curbstrap. I believe the lack of stop is because the cheeks are not fixed firmly to a solid noseband, leather straps just fold up, sides dig into horse face with no real leverage action. I have only seen them used by folks who see them as kind and fuzzy, no real knowledge of needing to STOP a powerful horse. Never see them at any Western activities, because they don’t work as needed to keep control of the horse. So do NOT buy this model:
http://www.jeffersequine.com/jeffers-hackamore/camid/EQU/cp/A8-DQ/cn/1101511/
I think you can finesse both the horse and BF, teach them a few new things, so they can cooperate on trail rides if you use the mechanical hackamore. It will let you have a more enjoyable ride, not worrying about BF losing control of a big horse who is not a beginner ride. Horse is comfortable, not being nagged in the mouth with untrained hands while you are out.