That halving the BPM is a great idea! I do it to with sextuplets. It is actually better for your timing than just playing one note per beat.
@Dominik Graeber (Or Chad for that matter). I checked out the first etude and decided to try it out myself. Besides practice, practice, practice...any suggestions? At 6:23 is where I halved the original 120 to 60 and played 1/8ths. Playing that note in between the clicker was honestly a lot more mentally challenging than I thought it would be. And I haven't even attempted the 16ths yet. But hopefully this is a good baseline to mark improvement off of down the road.