I really wanted a sub 10, but this is what I have for now.
I think the boss attacks are random, so if this is true a lot of variance will come due to RNG.
I did make some mistakes on skips, which would have made this sub 10 without them.
I don't know if it's faster to do the skip at the start or not, as you still have to fight the enemies either way.

Overall, I am satisfied with this run.