Interesting results from the cheap Poundland adhesive, but not unexpected.
Very good when putting a shock load (tugging in the same plane), but not very good on peel strength.
So for putting a patch over a rip it will be fine, so if you have a rip in the 'tunnel' a pole goes though, it will be fine for that.
What it would not be so good for is repairing where a guy rope attaches to. The forces here are too variable and some of them will cause peeling. So glue and stitch in those places.
The interesting part is that it does not seem affected by the fabric coating. My test pieces where some old waterproof over trousers.
They had a silvered PU coating on the inside and I suspect that the fabric is either nylon or polyester (I think nylon). Does not seem to make any difference if is is coating to coating, coating to non-coated or non-coated to non-coated.
I have bought, online, before I saw the Poundland product, some McNett's Aquasure shoe repairer, for a tenner a tube. Be interesting to see if this is any better in peel strength, but is is ten times the price, and price is no guarantee of quality.
I will buy another couple of tubes of the cheap stuff as unopened spares as it will definitely be good enough to get you out a hole.
Just as a quick update, I got my old sewing machine out, watched a YouTube about threading it, threaded it, and have done my first 3 rows of machine sewing ever.
The third row was through the glue line.
Works well.