If I had the 35-150 plus a smallish UWA I could do a lot of damage I reckon!
Exactly my thoughts; I rarely shoot under 35, so for me if I think at two different rigs:
R6 + 24-105 f2.8 (or 24-70 f2.8 or 28-70 f2 as it's the same for me here)
RP + 135 f1.8/2 OR 70-200 f2.8
Which is what I do today
OR
R6 (or a Sony...) with 35-150 f2-2.8
RP + RF16 or any 18mm or 20mm (there's EF 20 to adapt, but it's a so so lens) Canon could present in the future..or any Sony with a 18/20mm existing third party lens
If I'm thinking what I want to carry for 10+ hours on a wedding, I'll surely go for the second rig, is a no brainer; and the actual camera switches will be rare to say the least, so rare that I could probably just walk around with the R6 + 35-150 only, and keep the RP + wide angle ready in the bag on the floor, and take it out only when needed for a specific shot.
I couldn't walk around (size&weight aside for now) with just the 24-105, it's still too short, I would need a backup with more tele. And if I need to have a backup on me, it's better a wide angle backup then a tele, for the obvious size&weight reasons.
This is one of my wedding with 24-70 + 135, it's clear that I really start really shooting at 35mm, on 247 delivered pics, just 14 were shot under 35mm, and I reckon I shoot them "because the zoom was there", if my lens would have started at 35mm, I would probably have shot at that focal length the seven 30&28mm pics, just taking a step back, and probably I would have shoot those other seven 24mm pics at 16/18/20mm and then slightly crop.
I'm enthusiast too for the 24-105, don't get me wrong, it's a turning page, for sure; but even if I had the money (which I don't), I wouldn't buy it, because is not what fits me, it's not as flexible as a 35-150 for what I shoot. For what I do and how I do it, it doesn't give me anything more then the 24-70 or the 28-70.