Thanks for your replies everyone.
I spent a little while last night analysing my posture and hand positions. There is one piece where my wrist is definitely over bending and if I change fingerings I don't need to stretch fingers. It's also a tricky piece so I may be more tense than usual when attempting it!
I'm currently playing a sire v7 (one of the first models), the neck dive isn't really an issue, but I was wondering if the 7.5" radius might have something to do with it?
I also have a cort B5 with a much Flatter fingerboard, this is generally light and easy to get around.
The ibanez EHB look interesting. Not the usual look I would go for, but if I can get some time to get to a shop I'll definitely try them out alongside a shorty.
If things don't improve with my more conscious approach to posture I'll look in to a physio session. I'm also wanting to start with a real life teacher once covid retreats further. I'm sure they'll be able to spot any dodgy positions.