Tripod mount is a great addition (for 15 and 20 Laowa had a rotating frame), but for Tilt I cannot see use on such wide-angle except rarely needed pseudo-macro on such wide lens.
And shift-only version ergonomically much more convenient (it has rotating ring to shift also present in Hartblei Super-Rotators) than canon-style with knobs (never liked it on 17 TS-E or 24 TS-E wich I own).
So, one to rule them all 17 will be great (with someone make modern 28 or 35 - I had 35 shift from 1970s and it s not super sharp by modern standards), but 15+20 (or 24 - if you have Canon TS-E) will be more practical.
