The scrubland around here (New Forest area of southern England) is just at the right height to get a good grip on a kilt.

I'd not wear anything but a reverse pleated Kingussie style with an inverted pleat of two at least double width pleats centre back - so there is extra thickness across the seat area - and under apron pleats which are at least that depth so you have four layers of cloth at the front, and it is easy to step up or over.

I have a longer length of pleats than aprons, so the edges if the apron coincide with the joint of the thigh bone and hip girdle. That seems to give the greatest ease of movement.

These properties might not be so relevant in the heavy wool you intend to use. I'd be concerned about wearing a quality kilt in the wilds - It would not last long around here - but you should know your own trails well enough to decide on what fabric to use.

I use DPM, sturdy cotton very close woven for most of the kilts I am wearing every day.