I know this games pretty much dead but I found about 1.2 minutes worth of new skips.

Unfortunately the fact that I have to slow crawl through all the vents mitigates the time save.

I'm using the PC version. In settings enable "Always Run" and set Quality to Fantastic (Maximum). For some reason it doesn't work on lower qualities, at least for me.

First you might need to press shift in the beginning once to enable always running. When entering vents you might need to jump occasionally in order to "run" through it.

Hope this helps.

figured it out. it's a frame rate issue. on high fps it makes you slow in vents like I assume the devs intended? but on low fps like 60- it allows you to walk at the same speed you to normally uncrouched

Anyway know I gotta see if my other glitches work with low fps.