There are a few things where it could be better though.
Here's how I can keep, or not, the start of a cut line by MMB instead of LMB in Soft:
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Another thing, which is more general, not just for polysplit, is the Enter to complete thing. It's really disruptive, for any viewport creation process, not just for modeling.
Related to finishing the active cutting session, is the fact that once you finish it, it's really finished. What I mean by that, is that if you want to continue cutting but starting from somewhere else, you have to call another polysplit op. This is not a huge deal, although it would be cool to be able to commit w/o exiting the tool, by MMB, which currently toggles “edge snap” the same thing being achieved with the scroll wheel once you reach 1 divisions; nobody will go to 100 divisions to make this a necessity to have a hotkey for and besides, you can toggle manually should you ever increase the division # that much.
The “keep starting point” feature shown in the .gifs above, could be activated by ctrl+LMB.
In the lower viewport area where the tool tips are, it says “hold ctrl to disable edge snapping” and nothing changes.
At first I thought it's an actual edge snapping disable feature, in case you want to place a point very close to an edge, but apparently it refers to snapping to the divisions when they're active. Which you can already disable with MMB. Or maybe that was the intention - actual edge snapping disable - and it's not working due to a bug.
Either way, I don't think such a feature is needed - one can just zoom in a lot if you want to place a point very close to an edge, 99.99% of the time you want the edge snapping active. Disabling the edge snap (again, not snapping to the edge divisions) should be achieved with that toggle “Edge Snap” currently made with MMB and also with the scroll-wheel down. Very confusing due to redundancy, a possible bug and unclear naming.
Should anyone feel like I'm talking in riddles here, let me know and I'll try to clarify this with pictures.
Now, again, apart from the problems described in the paragraph above, this tool is actually very well implemented and thought out and should the said problems be sorted out, it will probably become the best poly-cut tool in the industry.
p.s. Just an FYI: the “edge divisions” input box accepts negative numbers and even goes there with the scroll wheel once you manually input a value <=1.