Currently, loopcut is done in 2 steps.
- pick the loop to cut.
- slide the edge loop.
In some ways this is good, you make 2 separate decisions quickly without fidgeting with the cursor to put a loop in some place which might be difficult to locate exactly.
Currently the cut is always exactly in the middle, this isn't always a bad thing - sometimes you want a cut in the middle so in that case you can simply do Ctrl+R, LMB,LMB
This design ticket proposed that it be changed so the initial pink-preview loop is aligned to the mouse cursor, this way the default behavior would be to add where you click, and if you want the loop to be exactly centered you could hold Ctrl to snap it to the center.
We can also make it so holding Ctrl while selecting a loop keeps the existing behavior. (This matches knife's midpoint snapping).
The only drawbacks I can think of are...
- if you prefer old behavior as default and are adding a lot of central loop cuts.
- if you want to add a loop where many edges meet or overlap, its can be hard to select the right edge and the right % in one step, In that case you can still add-and-slide, but this behavior would mean users would get into a habit of adding directly and double clicking, and in some cases there is a bit of a conflict attempting to make both decisions in one step.
- Behavior with multi-cut - I would match current behavior with multi-cut and slide, but I can imagine this would feel a bit awkward from a user perspective.