Of course splitting a flow is a fast way of going about things but I don’t think the issue here is about the ease, or lack of it when it comes to getting rid of cautionary marks. It’s that the current solution - create a new flow - is not one that suits some users.
For the most part, Dorico is incredibly flexible. It’s understandable that when it isn’t, and it isn’t by design on an issue where users want the flexibility, it’ll surface time and again on this forum.
Personally, I’ve just come to accept this is how the team at Dorico wants to handle this issue. Their software, their solutions. It is possible to work round it.