EZiniT .

A hip file would be a whole lot easier to diagnose tbh.

I don't seem to be able to replicate the issue seen here.

(Attached) a basic curve setup for a weaved material effect, .

The labs "visualise vector" node can be used to show vectors more clearly and you can set the thickness
overall by pressing "d" in the viewport "geometry tab" wire width.....
(this doesn't work for default visualisers and will change "all" wire widths)

No doubt there is a setting buried somewhere in the UI or a system file as you mentioned for the viewport visualization
vectors but tbh no idea where.

I normally set my background to dark grey and never really had an issue seeing visualizer vectors on 4K as long as I set
the vector colour to something complementary.

https://www.sidefx.com/forum/topic/102904/ [www.sidefx.com]

I also had a few BSOD errors very recently while rendering with XPU and seems the above post is the reason if
you're still experiencing them.

The Houdini folder in documents on windows is normally the first thing to get corrupted through normal
use or crashes, first course of action I found best is delete/rename that, when Houdini starts up it will make
a fresh one rather than go through the long winded process of uninstall/reinstall.

Obviously this requires configuring Houdini again from default settings so making a copy of that
folder while things are setup and working well then simply swapping it out if/when things go wrong will save a lot time.