I have several old high jump crash mats (for free) that have been decommissioned from original purpose use. A bit tatty but will take a three metre horizontal uncontrolled fall. Easy to fab up a cover for if u want – old hammocks do the trick.
they measure 0.5m thick, 1.5m wide, 1.8m long… ish
They are located in Thornlie. Reply if you want any
cheers