Hey, thanks for the feedback! I noticed the bug that lets you clear a line in midair shortly after uploading the update, but I didn't catch that it could cause a softlock! I'll work on patching these out, hopefully by the end of the week.
The first point about solving mid-air tetrominoes is actually intended behavior, as many people were finding it impossible to catch up when their tetris stack outpaced their solved area. I may need to increase the spawn rate of mines on the edges to nerf this a bit, since it's currently very common to get large 0-cascade areas on the sides.