I completely agree with you on this, though I couldn't find a great way to do it. It was suggested to me to put an outline around the allocation or free that just happened, but I struggled to get the box to look good when the allocation was split across 2 lines.

I've started writing my next post and have learnt a bit more about PixiJS/GSAP3, and think I know a way to do it that would work nicely but would require changing some of the underlying code. I can't promise I'll revisit this soon, but I would like to in future.