Using Dynamic draw while orienting on surface

Hi Everyone.
I was working around the dynamic display in RhinoPython starting with the point display provided as an example, trying to adapt it to the following problem but without any success. I need to be able to move a circle center with the mouse while constraining it to a non planar polysurface, with the preview circle plane and circle remaining tangent to the surface at the center point as it moves. Has anyone encountered and solved this ?
Thanks !

Hi Phil, it’s been a while I played with dynamic display, but I made a few examples that you can find on my GitHub:

Maybe it helps. The dynamic curve on surface example should be a good start for what you need.

Thanks Gijs, I’ll play around with it and see if I can adapt something ( or just better understand the intricacies of dynamic draw ;o) Cheers