Now this is the content I come to HN for. A serious hack just days after the 4 was released. Kudos to the OP.
I envy people like OP for their tenacity. I barely have time to follow what's happening in IT, much less get ahead of the pack in doing cools hacks like this.
On the other hand, the fact that the RPi ecosystem remains notoriously proprietary (even the USB controller is a bastard variant that has next to no documentation --- of all the ones available, they had to choose that one) continues to be disappointing.
I definitely like this sort of hack, but such hacks with documentation already available (and doing more than documented, basically) are certainly preferable.
Of course! HN is just a good digest of things on the maker side to the fairly abstract CS stuff to math and physics and all in between. It sure beats the political stuff that becomes tiresome (even though I succumb and engage in it like many posters here).
I envy people like OP for their tenacity. I barely have time to follow what's happening in IT, much less get ahead of the pack in doing cools hacks like this.