While I don’t feel your current cam is as good as can be had for your goals, it wouldn’t be way up on the list of things that needed changing either(a pair of matching carbs would be higher on my list).
As for the 10deg split.......
Ask yourself what part of the engines power band would you like to improve the most....... and how does that 10 extra degrees of exhaust duration fit in with that goal?
Where you want to make more power, and where I might want to make more power....... may not be on the same page.
In either case, that extra ex duration isn’t having much affect on the output one way or the other.
It’s a minor tweak.