Hi Chuck, Welcome to the Forum, glad to have you here.
Footstraps are very common in one of my two climbing worlds (caving) but I know of no one, personally, in the tree climbing arena that uses them. I think the reason is that you have to carry them around in the tree clipped to you, or throw them to the ground once you get up there and then not have them if you need them again.
The length of webbing from the ascender to the footstrap, and the footstrap itself would add a fair degree of bulk if you were to schlepp it all around the tree, especially if you're packing a rack of slings and biners for rigging purposes, and a Silky or two, and a chainsaw. Guys who want this sort of aid generally use a foot ascender called a Pantin.
Pantin or footstrap, even though it may make the ascent easier, still adds extra gear, and added complexity. Remember, the ascent is only a small fraction of most any given climb. Most of the climbing in a tree is climbing the tree, not climbing the rope.
The beauty of ascenders linked to your frontware is simplicity and minimalism. Footlocking and ascender(s) is a system boiled down to the least common denominator. Learning to use an ascender is, well, let's say there's a very, very short learning curve, which means almost all the skill is in learning the footlock. The footlock, as a technique, is very straight-forward; rope over one foot, under the other. That's all there is, really.
It doesn't take a special athlete to do a proper footlock, nor does it require some innate skill that some have and some don't. No special gear is required. If you are having problems learning the footlock, it probably is not you; it is likely your footwear. I honestly believe ANYONE can learn to footlock well, but footlocking with improper footwear is akin to eating soup with a knife.
Attached is Elizabeth's rig (partial). Very effective for anyone who doesn't climb regularly. It's a two-foot footloop.
I will do anything I can for any one of you to help you get comfortable footlocking.
Much of the hurdle, early on, may be mental. Maybe it's the way you've got your setup rigged. Partly, it could be your climbing boots. Let's troubleshoot, source where the problems lie, and get you comfortable doing this. Once you get it, it's like a young bird learning to fly. Soon it becomes second nature.
