Bass drone at 45 degree angle? Yes
Blowpipe in center of mouth? Yes
Chanter position centered? Yes
Squeezing Arm impinged? No
Frantic blowing cadence? No
Drones out of tune (with each other)? No
Overall Basic Instrument Operation Comments from Timothy Gatehouse: This is definitely a good one! Posture points are quite good, very close but not quite "perfect". I say this only because I notice that your bag arm shoulder being hitched up higher than it needs to be. Let's see if relaxing that left shoulder gives you a better neck position. It's not a game breaker, mind ye... Just something that you'll find to be more comfortable in the long run.
This might also be of help, looking at your bag arm wrist, it's got a bit of a kink. Again, not game breaking. Try setting your arm down on a table and just relax it fully. See that your wrist naturally falls straight, with your fingers neither open or closed? That's the position we want to achieve.
While they were "close enough for government work" I am still able to hear a tiny bit of wavering in your drones out still. It is probably that last millimeter on the bass drone, as your breathing cadence is really quite good at this time. Listen back to your video and you'll be able to hear a faint bit of higher pitched oscillation (Not even a "nyun-nyun" as I call it, but just a "ninin" if that description helps) in your very close drones.
In any event, this is still a pass! As you work on your phase 4, Don't hesitate to drop me a note on Discord if you'd like some help with improving these finer points! @Timothy-Gatehouse