Hey there! Sorry for the late reply, I’ve just seen your post.
Well, thanks for the kind words, really appreciate it. Handling collisions with non-axis-aligned geometries has by far been the most difficult thing I got to implement for my engine! Lots of late-night debugging sessions and pulling my hair out due to the inaccuracies caused by floating-point rounding errors, haha! I’m glad how it turned out though. As for the collisions against the y-axis, you are right, they are non-existent right now. That seems a lot more straightforward though, when compared to handling collisions in the x-z plane.
As for the mouselook issue, I haven’t really invested in resolving that one since I would have no real way of verifying/testing my fix as I have never been able to reproduce the issue on my end, sadly.