The new behavior is vulnerable to fast movements. You need to move the mouse pointer slowly, otherwise the tool will skip some lines on its way. Sometimes those skipped lines would be in the middle and sometimes it would be the last line it crosses.

Yes there's not much way around this, it's because mouseMove triggers only so often. So if mouse goes too fast it won't catch all

I tested this, works really well. It's a handy feature. @PaddleStroke Can you undraft it if it's ready?

Hello.
What if this tool instead of trimming edges directly (in continuous mode) would draw polyline, and then edges which cross this polyline would be trimmed?
It can solve mouseMove triggering problem.

Hi and thanks for your suggestion.
I see what you're suggesting. It's how it works in fusion if I recall correctly.
Drawing a line is not a problem. The problem is more how do you know which edge is crossed. And it needs quite a rework of the tool. While this PR was simpler to do as it was modifying the current tool only a little bit. Making as you suggest is a much larger work that I can't do right now.
But if someone wants a project to tackle, feel free to grab this :)