If I want to prevent shorts from borrowing a specific stock I have, am I able to set a high limit sell price? Or is it the distance limit that stops me from doing this?
It makes no difference. Stock can still be lent. Lending the stock does not prevent your limit order being valid, or vice versa.
OK, thanks for explaining. Still learning here…
you are not owner of the stocks if you bought them via T212
This is incorrect. You are indeed the beneficial owner. Check the HMRC requirements imposed on ISA managers.