In my opinion this is a problem because it becomes more difficult to find the right match when you have to insert a 3D model on a photo..isn't that the case for you too?
Yeah, it's a major pain. Not being able to match lighting/level/hues against backplates because of tonemapping that can't be worked back is really a problem in my case and almost every project suffers here because I can't be sure I'm 100% where it needs to be.
In case you wanna vote for it:
https://chaoscorona.ideas.aha.io/ideas/CMAX-I-27For some reason, the team never properly acknowledged the need for unchanged background colors, and it surely can get complicated. But even a simple solution, even if limited, would help.
Don't get your hopes up though, people want stars and the moon in the VFB and I bet it's going to be there way sooner.