Not too sure where you are on the foot control levers, but going to pass a couple of things along early just in case. First, and this may be obvious, the lever arm that pulls the brake rod needs to be at 90o or greater to the rod. This looks to not be possible with the lever in your pics as you will want the pedal to be angled down considerably with the brake not being applied. The actuating arm would need to be rotated anti-clockwise considerably to be in an appropriate range. The second less obvious but potentially more important issue is the location in space of the pivot between the pull rod and the actuating lever. Ideally, this would be directly coincident with the swing arm pivot. In this location, movement of the suspension will not affect the action of the brake. Moving away from this location in any direction will cause motion in the brake mechanism when the suspension moves. Generally it is extremely inconvenient to locate the pivot in this ideal spot, but moving it rearward along a line between the SA pivot and the rear axle has only very minor impact. You can not move the pivot up or down from this line very far at all without very noticeable "pumping" of the pedal as the suspension follows bumps in the road. Move the pivot far enough and the brake can actually become applied with enough suspension movement - very bad! One common solution is to use a cable like that used on the front which eliminates this problem completely, but is a lot more complex than the simple rod and lever scheme.
Personally, I spend a LOT of time sorting out the riding position. The person who will be riding the bike needs to spend at least 15 - 20 -30 minutes sitting on the bike, with the seat at the correct height, hands on the bars selected and adjusted, and feet on mock ups in the expected position. That would be a pretty short ride, but will indicate if changes are wanted. It does not factor in wind resistance, but in my experience, that is less important a factor on setting the ergonomics than is popularly thought.
Of course, getting the seat, bars and pegs just right with no concern for the associated machinery invariably makes for a lot of fabrication work to get all the controls to work equally well. I think it is worth the effort to have a bike that is really comfortable and fits your purpose perfectly.