Ok, good point.

Now i have found my old editor sources which use glLoadName methods for picking and TTimer with interval of 2ms for drawing map. I have 0 CPU most of the time, and goes up to 20-60 maybe when drawing something or rotating or something else.
Of course 1-2 is too quick and standard ttimer cant even handle that properly but if i will use threadedtimer with interval 16-17 for example, dunno if that will make ray picking slower? I guess not.

Again, why i have timer with 2ms (ie. drawing map each 2ms) its because of the picking method i use and because of the "tile painting" in my editor. User can "paint" tiles on terrain. If i set timer to 20-30ms then this picking and drawing gets very slow. The painted tiles will appear with very big delay on terrain and may even not appear at all. Because if user moves mouse too fast then it cant even catch all these coordinates so quickly because low timer interval.

This is how i did things before (~2007-~2011) i found nxPascal.

Im talking about the old editor from my backups.
The current one uses game loop but eats cpu always, even if its minimized or not active at all.

Dunno how it would be with TTimer or threadedtimer with interval of 30ms and ray picking from nxPascal.
I have to test.