Gen 4 Glock 21, will interchangeable backstraps illiminate the G21 SF?

I was looking at the G21 SF. I have smaller hands and the G21 grip is just too big for me to control easily. Anyway, the Generation 4 G21 has the interchangeable back straps. My question is does the small insert on the Gen 4 G21 equate in size to the G21 SF? Or if I want a Gen 4 G21 SF I just need to wait til they come out with it?

Thanks.

With the smallest backstrap, the Gen4 G21 frame is the same size as the G21SF.

With the release of the gen4, the SF is obsolete.

There won’t be a Gen4 SF since the naked Gen4 frame is the same size. The real differences are in the recoil spring and trigger group. Some prefer the Gen4 but I stick with the Gen3 SF models and couldn’t be happier.

The Gen 4 without a backstrap will feel noticeably smaller than a 21sf.