If anyone remembers, I had knee tendonitis for months and months straight. I tried many different stretches and exercises, but in the end, NOTHING helped more than simply foam rolling the IT bands, and then activating my VMO's, then ATG squatting. After squat sessions I would remember both my VMO's being very sore. Now the soreness is gone as they are used to the stress, but they will grow as my squat grows.
I haven't read this entire thread, but maverickdawid, have you tried foam rolling your IT bands? Do about 4 sets of 10 slow rolls back and forth and see how it feels. After that I would activate my VMO's and then do my workout or go play basketball.
Also, the best VMO activation I found was doing single leg knee extensions, but only the negatives. You REALLY gotta load it... bring up the bar with two feet, then drop one of your feet, and lower it slowly with the other foot. I have read that activation works better when doing heavy negatives and I tried it out. Ended up working for me.