I'm not sure if this is significant or not, but I did a 3 frame clip into the ground in 8-2.

You can't clip in enough to clip into the ground. You need to have upwards or no speed to fully clip into a block with no block over it.

Thank you, I was wondering if this was important or not, thanks for telling me!

If it was possible to clip into the ground while falling, then we would be doing FFPG in 8-3 (and other levels)