Great to know about the mouse wheel, but that doesn't work with a touchpad.

When splitting a file I play with the seconds, 10s of seconds, fraction of section digits frequently. I would love if when the focus is on the seconds digit if I clicked up arrow it moved the number up 1, down arrow down 1, right arrow move to 10ths of seconds digit, left arrow 10 seconds digit. I w...

I don't know what happened, but it's back to normal again. Very weird.

I put in OutputFilename in the field and the list of files I get are now:
OutputFilename.mp4
OutputFilename (2).mp4
OutputFilename (3).mp4
OutputFilename (4).mp4
...

I used to get as you state above:
OutputFilename - 1ofX.mp4
...

Looks like the split output is no longer adding XofY to the end of the filenames.