Inconsistent sprite behaviour with on wall settings

The sprite settings bounce on wall and destroy on wall have inconsistent behaviour when there’s no tilemap and the screen edge becomes an “implicit wall” in some cases:

  • sprites bounce off the edge of the screen with bounce on wall ,
  • sprites travel off screen and continue to exist with destroy on wall.

This can be seen in this small demonstration program where the cyan duck should die but makes a fleeting comeback proving there’s life after going off screen:

There’s also a change in behaviour from production beta to beta beta with a sprite with an acceleration value with is then later set to follow another sprite. Watch the green duck. Which one is correct?

On reflection the following on 0.14.45 must be broken. I put in GH: microsoft/pxt-arcade: follow sprite behaviour looks broken in 0.14.45 and absence of unfollow block #1505 for this.