In reply to MNA123:
You can get suitable fabrics from these
https://www.profabrics.co.uk/ but they sell it by the metre and the rolls are about 1.5m wide so you'll have a lot spare!
Aren't most mats made of cordura rather than ripstop polyester? I don't boulder much but I don't recall seeing a mat that wasn't made of cordura or something similar.
I can't imagine glue holding though, perhaps Tenacious Tape might https://tinyurl.com/y5wh2pb5
Never used it myself but it regularly gets recommended on here. Ideally you'd sew it but you'd need to take the foam out and have a sewing machine (or take it to a sewing repair shop).
Regarding the repair, I'd put the patch on the inside of the hole, i.e. so its between the outer fabric and the foam so you can see it through the hole. That way the edges of the patch aren't exposed and can't get ripped off if they catch on something.