I don't know why we all worry about sharp curves.
It doesn't seem to bother Network Rail :
(https://www.ngaugeforum.co.uk/SMFN/gallery/104/230-120121192218.jpeg) (https://www.ngaugeforum.co.uk/SMFN/index.php?action=gallery;sa=view&id=104603)
I think a speed restriction will be required here.
At least the pic was taken from the right angle