I appreciate the advice.
Just to be clear I wasn't suggesting that silicone be used to glue down the rubber. I said it could be put over the few mm of partially exposed pink batten near the corner. And glue can be used to adhere the membrane to the deck, this is part of the process although, yes, even the proper stuff can of limited utility as rubber doesn't like to stick to things.
Yes, the membrane needs to be extended. I don't think extending it from its current edge is a good idea as this is literally at a point where it needs to fold over the side of the roof and down towards the fascia. And it is on the side of the roof where torrents of water run off into the gutter. So most likely it could do with being cut back by a foot and then joined to a new piece of rubber on a flat area of the deck. Agreed?
The problem I have is that I don't trust the roofer, with whom I have a guarantee, to do this properly. And I need a roofer who:
A) is willing to fix a problem caused by somebody else.
B) is competent.
C) isn't a total scumbag.
The above will be a challenge. The roofing game seems to be full of scum. The ones who are competent are incredibly expensive and hard to pin down to do work at short notice, and I don't have a spare 1500 quid or whatever they'll want to sort this - assuming they are willing to, which they probably won't be. And I certainly don't have the 4 or 5 grand a properly trained roofer will want to do it all again.
So for now, I need get it so it is stable and water tight for a while. Despite what people are saying, water CANNOT get in if the rubber is correctly pinned down, even if it is short. I am referring to my case. I'm not saying it should be like this I am saying water cannot get in and have explained why in previous posts. There is no evidence at all of wet under the rubber, even after nearly two years.