You’ve got to love STW. Somebody asks a simple question and everybody wades in with their prejudices 🙂
I read something on a thread about Orange frames where somebody claimed that a single pivot would make it easier to make a 29er in small sizes. Not sure if that is true, but it’s a thought.
I suspect that the rear suspension isn’t the big issue though and it is more tricky to get the frond end right. The main issues are bar height and avoiding too much toe overlap I guess. So, I’d be looking for something with a short head tube but long top tube. Whyte bikes generally have longer top tubes than most and the M109 in small has a 100mm head tube, which is probably as short as you are going to get. So, I think I’d start there.