I don't know if you've read everything in the thread, but it is *not* "so much easier to cut the film to size."
Originally Posted by fotch
1. The conversion takes 20 minutes, as per one of the links above suggested: How many 3x4s can you cut from an 8x10 in a darkroom that some of us don't have or a dark bag where you can barely squeeze in a paper cutter in 20 minutes?
2. The conversion is semi-permanent: once you do it, you're set. You can use 4x5 film or 3x4 instant, or any of the roll film backs up to 6x12 to your heart's content; cutting film to size has to be done every single time you want to shoot, for the rest of your life
3. The 4x5 that comes out of your converted back can be easily developed at your developers (at least any of them that do 4x5); like the OP says, not always the case with 3x4
4. The 4x5 that comes out of your converted back can be easily scanned on your Epson flatbed (or Imacon) scanners with 4x5 holders; with 3x4 film, you are on your own to DIY a 3x4 holder
5. The modification is non-destructive (despite how some people are insisting on calling it "butchering") and 100% reversible
It's funny how y'all have these elaborate "workarounds" to make this near-obsolete technology work in the modern-day and yet would accuse those of us looking for a simple, one-time solution to the problem as somehow "going through all the trouble"