Well the reason I was talking about limits that way is because it's something screens already do when displaying HDR content. They can't go full power over much area, and the bigger you go the dimmer your limit gets. So repurposing those existing algorithms with some tweaking.

It's not very hard on a technical level.

And no it doesn't have to be universal and perfect to reach the point that HDR is a benefit. There are some blatant flaws that need fixing, and just a few fixes would get us a lot closer.