What would you do?

Hi all, looking for some advice. I’m resealing my shower currently, I’ve managed to remove all/most of the silicone today ready for resealing tomorrow. However, the shower tray isn’t square with the wall (presumably the wall isn’t square and I think the previous owner installed all of this himself).

My question is how would you deal with the varying gap? I was just going to put a big old wedge of silicone on it with a 45deg chamfer to try to stop water pooling on it (before I dug it out it was just flat silicone), but I thought I’d ask on here for other options/opinions, the only thing I can think of is to make up some sort of filler piece but then you’re still probably going to have to rely on some flat silicone to seal at least part of it?

The gap is probably 1.5-2cm at its widest and currently has what seems like foam pipe lagging type material to take up most of the space.

What would you do? Thanks!