The Glitch Effect happens in a few instances in the game, the main one being hitting an enemy with the laser. It will freeze everything(except the dump timer) for 4 frames or 0.066... seconds. Minimizing glitches can slightly speed up your time.

RNGsus

Now that we know exactly how long the game pauses for when a hit occurs, we can show that not killing Jesus is not that good of a timesave. Since it takes 19 hits to kill Jesus, you only gain 19 * 4 / 60 = 1.266... seconds from it, helpful for super-optimal play. Since you can sometimes lose your run due to impossible enemy patterns, it's still not worth it most of the time but go for it if you want.

Act 1 Post-Laser Enemies

A significantly more easy to perform optimization is once getting the Laser in Act 1 is to wait until as long as possible to finish off each wave of enemies, since the next wave only arrives when the previous one is completely killed, meaning less enemies to kill per level, meaning less Glitch Effect slowdown. Comparing my 35:18 run to Laurie's 35:04 run, I only get 21 waves of enemies where he gets 31. Or, in actual enemy count,(this is not an exact timesave since his RNG for the amount of enemies was significantly worse) I get 127 where he had to kill 208, a difference of 81 enemies or 5.4 seconds. How long to wait before the enemies attack you? I counted it to be exactly 180 frames or 3 seconds, the Glitch Effect will delay that by 4 frames as usual. Try to delay killing each wave as close as possible to 3 seconds without dying, since that can speed up things a lot. (This can also save even more time in the Any% No Major Skips and All Tickets% categories as well since Adventure Mode is full of this).

Wings (barely useful)

Activating wings will cause a glitch effect which if done unnecessarily can cost you a couple frames. In the Any% run this only happens in Louey's section once the game begins to break and Devil Island. Not really that helpful, but I thought I might as well make a note of it.

Dump

There is nothing you can do to speed up or slow down the system dump. I've tested everything, and none of it will change it, once you've hit dump start your time is already set.