Basically any box available in the makeitgood editor (trackzones, triggers, etc...) start heavy flickering after moving the camera around or waiting for a while, which makes me believe it's tied to some physics related thing while in a level rather then an actual issue with the renderer that was working fine last year (can't pinpoint the release of the regression, sorry). This issue is present with any glprofile using the shaders renderer, but does not occur with the legacy renderer which works fine (except you can't see the yellow trackzone that's inside a blue trackzone and a few other instances where you can't see a certain trackzone inside another). It's not the usual flicker as in when 2 polygons share the same spot with different texture because while the trackzones overlap, they do not overlap precisely but there is a big gap between the faces of the 2 boxes and yet I have this strange flicker where the game tries to display one and then the other trackzone/whatever box I'm looking at.
Described behaviour + f9 debug menu in the video (may need a few moments until yt finishes processing, I'm sorry for crap quality but I was messing around with encoding settings and it looks like obs doesn't like 120 fps recordings)
Report issues and bugs here.
I can acknowledge such issues exist with the shader renderer. My recommendation is to stick to legacy renderer when using MIG modes.