Is Smart Redraw activated by default (re: dirtyregions, subtitles, idle temps)

Well I used an empty advanced settings for the past 1.5 years and the subtitles were the only real issue I ever had with the Vero 4k. Others had the same issue here:

It never really resolved until I added the dirtyregions 0 setting in late August. And I saw on other forums, that this was the only workaround that anyone could find.

So I used that the last two weeks and was impressed by the much better subtitle performance. However I then noticed the significantly higher idle temp. Which is per se also not surprising because that is what should happen with no dirtyregions… however since Leia we have smart redraw and the question came up why it seems to be not working with dirtyregions diabled… or why the disabling dirtyregions still has an effect and is not really retired?

In other words: the whole thing is new and a total black box and the solutions I found have downsides. I wanted to post it here first because I know you guys would listen and maybe also have the knowledge or the onnections to investigate.