The autosizing on the conversion queue is perfect, and looks great!
The margins on the progress bar could be reduced a bit more, though.
I’m referring to the text showing the current file being processed.
It can be demonstrated when you expand the width of the MCEBuddy window.
It also looks like there is a large overall margin for the window itself. For some reason, the right side looks bigger than the left.
I suggest making the left and right margins of the window the same (small, but reasonable) as your top and bottom margins. That gives you the maximum area for displaying information, but not looking over-crowded.
Here are some screenshots with indicators:
Default window:
Expanded a bit more to show the expansion in the progress title margins:
Expanded enough to show the full filename being processed:
P.S. Pay no mind to those ridiculous estimated completion times. This is CPU-only AV1 encoding on an ancient Haswell (4th generation) i5-4430 from circa 2015. Yeah, time to upgrade, I know. But it ain’t broke.