I have a 5.60 kart (Plume Spirit) without seatbelt, nor device to protect feets/legs. See picture below (not me in the picture, but a real champion).
Those things go real fast, and according to Blokart friends, and in line with www.seabreeze.com.au/forums/Land-Yacht-Sailing/Construction , I will work to add a seat belt.
I wonder if I should also design something to block a bit the feets to avoid reflex moving the leg in case of capsize. I wonder if the LLM seat with its small sides at feets level has that function or not, and is sufficient or not.
Advices welcomed to avoid issues in case of capsize and improve the odds to be able to practice for many years ;-)
as far as feet are concerned Just fit a strap as per blokart,mainly to stop you inadvertantly putting feet onto floor and breaking ankle . Theres enough protection from the frame. With belts,yes you will stay with the yacht,but do you want to,I'd rather be spun out of it instead of tumbling over still trapped in it,and having ended up in the surf two or three times glad I could just jump off .Others will have different views ,each to thier own. good luck.