Thanks, Lev. I found that pretty useful, and he had some good tips, particularly that it's good to focus on one or two modes rather than to learn every single one all at once. One mistake (I think) that I noticed in the video is that the lydian mode has a sharped 4, not a flatted 5.
What I've found with modes is that they are simultaneously more simple and more complicated than I initially thought. You can think about them in about a zillion different ways, whether it's learning them as scales, shifting your major scale pattern, shifting the tonal center, or whatever. To really firmly grasp what you're doing is, to me, kind of difficult and it takes some time. However, the basic concept is really simple: same pattern, different root.
So thanks again for posting these. Useful stuff.