WRT the “Fixed not being able to swap lines down with the last line if it was empty” fix from build 3211:
So, indeed, now you can swap down, but you can’t swap up.
Reproduction:
Swap line 1 with 2. (ctrl-shift-down for me)
Swap line 2 with 1. (ctrl-shift-up for me) ← this does not work
Note that if lines 1 and 2 are swapped, and you’re switching around the line with the a on it, step 2 works fine.