Currently the splitter editor will automatically re-arrange th epin mapping whenever the fan-out or bit-width changes, forcing (most times) a re-edit of the existing signal mappings. It would improve the ergonomics if whenever fan out is increased, the new output is marked as 'none' and all the remaining mappings stay un-touched.
Similarily, changes in bit width should also have as minimal an impact on the current mapping as possible. So, increasing the bit width would simply append the new bits and automatically mark them as 'none' mapped, etc. The goal is to have as little possible impact on existing mappings as possible when editing.
ie: Change only what needs to be changed, don't touch the rest.
I am frequently doing circuits with the full 32-bit and multi-fan-out splitters and every time I need to increase/decrease fan-out, I am forced to completey re-edit the current mapping. Very time consuming and error prone.
Note: An additional minor addition would be a short-cut key that, when in th edit window of a splitter, quickly allows me to set all pin mappings to 'none'.
I find this helps a lot when having to re-map a splitter. Im effect, all signals mapped as 'none' show immediately that I have not yet mapped them. This would be much quicker than the current method of having to go through all signals one-by-one and use the mouse to select 'none'.