TeamCity DSL and branching

I've stored all my project settings in a code. I use BuildSettingsMode.PREFER_SETTINGS_FROM_VCS rule. When I change any build step, this change is respected on all branches, including feature branches.

However, when I introduce a new build, I add it to the chain and merge my branch. Since all other open pull requests still don't have this change, starting builds using these branches will result to failure: TC will complain that such build does not exist ("Failed to load build configuration settings from VCS: build configuration config is not found, use current settings from TeamCity server"). All current branches must be rebased onto default branch to make things work properly.

Similar thing when I delete a build from a build chain. Older branches would still refer to an already non existing build and fail because of missing dependency.

Is there any possibility we can merge the default branch to the current branch when build start to make sure all the latest build settings are applied?