A sear only costs about $12 and I have some extra available so I gave it a shot. Bottom line is it made a huge difference and the reset is so dead on I got paranoid and added about 1/32" of pre travel just to make myself feel better.
what the video is trying to tell you is the surface of the trigger bar and sear leg aren't mated well. bot are fairly rough and the angles are a bit wrong. So basically if you have the sear leg and trigger bar faces parallel and still rough the bar has to move until it doesn't contact the sear leg in order for it to pop up and reset. It basically hangs on the edge of the sear until the last minute. So it looks like this, ||.
If you put a relief cut on the sear leg and make the faces flat and smooth you kind of make a very slight chamfer that allows the trigger bar to rise sooner and stay in contact with the sear leg. So it looks like this /|. Of course this is an exaggerate angle to illustrate the point. Basically you want about 1 degree for each. Think of it like a mag well. In his video he says to put a relief cut on the trigger bar leg too, but I don't think it's necessary. YMMV.
The challenge is making the slight adjustment to the angle without going to far or messing it up. You can probably do it by just applying more pressure to the bottom of the leg with the stone, but it's such a small surface and the body of the sear gets in the way that it's cumbersome. I tried it this way at first and the results weren't great. I happen to have a power custom series I jig with a 1911 adapter. I put the sear on it and rotated the adapter until I had the right angle and cut it again. Using the jig I was able to be really precise.
This time the difference was dramatic. It worked so well I did the same to my SAO shadow that I use for IDPA ESP. Both have almost no pre travel. And really it's just my own paranoia that led me to keep just a hair of pretravel in place.