High myopic with a high base curve. Help!

[rimless glasses frames]

First of all sorry if something like this has been posted before; I did search but did not find anything. I'm a dispensing optician working as a lab technician part time and training as an optometrist.
My dad's rx is:
RE: -7.00 DS
LE: -6.00/-0.50 x 175
Add +2.25

My dad used to wear comfort frame which he loved. His optometrist changed him to a Panamic which he didn’t like as much. He now wears a Physic which is better but he still preferred the Comfort. Now I'm thinking of going for a 1.67. The problem is that he has chosen a rimless frame with a 4 base front curve and he wants to match that curve/wrap around look. If I were to go for a 4 base 1.67 would that curvature cause more distortion? Usually I would have used a 1.75 base but he wants the curvature!
My question is that would this curvature with this rx cause any discomfort (excuse the pun)? Any ideas?