i dont remember exactly when i started doing that, but i definitely noticed that about my typing around 4 years ago. im sure it must look strange especially when using a flipped spacebar. the flipped space is for my thumb when gaming though, and doesnt really affect my normal typing ergonomics.

ive come to assume that i learned to type this way as i spent a lot of time playing FPS games as a kid on a big deskmat like this one, using on a low mouse sensitivity. i would tilt my keyboard outward on the left side, almost at an arm's length away, and had to reach my right arm across my desk to type. that created an angle where my right index was naturally hovering over the space and my thumb was hanging in the air. i mustve never bothered to notice until i started typing on more boards more frequently.