Well, depending on who you ask you might get different answers. However, I would generally advocate to get the most basic features right first, which apply in many cases, before tackling more advanced or esoteric features, which only apply to edge-cases.
In the case of your list I would say:
#1: This is super important. Currently, UV mapping basically breaks when you have an odd # of bevel segments.
#2: Seems like less of an issue?
#3: You could always continue to keep adding miter types. But given that you’ve already developed many new useful miter types, you could start by just adding in the ones you’ve got, which may be good enough for now. More could always be added later
#4: This would have a huge impact in many common cases that currently fail, when you have too dense geometry before a bevel.
#5: This is massively applicable in many common use-cases. Both for special shapes, but also just because it’s a nice way to accurately visualize your bevel profile vs the ‘Profile’ value, which is not super clear.
So, here’s how I would stack your todo’s in order of importance to most end-users:
1: #1: Tie-breaking rules for materials and UV seams with odd # of segments
2: #4: bevel flow past existing edges
3: #5: Custom profile curves
4: #2 “termination” pattern types
5: #3 The polar miter type
And I would probably add the beveled extrude feature somewhere near the top of that list too, as that is a very basic operation too.
Obviously, all of your todo items seem like nice things to do, but the above order I think reflects roughly on what would have the most useful impact for most users on most projects.