I have my Robertson Wolfer, 58”, 50# @ 28”, set up for 3 under with a fixed crawl. It is a 2 piece recurve with long working limbs and a short riser, and works great with that setup. I’m sure my Ron LaClair Shrew longbow would work just fine too, although I haven’t set it up that way. It is a one piece bow that also has long working limbs and a short riser. I have other 58” bows with shorter working limbs and longer risers that I notice are beginning to stack at 28”, and I would not set them up with a fixed crawl. Some people who really like short bows have no doubt pushed it even further, but I really have no experience or desire to shoot bows shorter than 58”.