No overlay icons displayed for branches in subdirectories (scmproj)

I've been using the scmproj plugin for some time to manage a tree of a couple of branches. Since I'm partially working on Windows, I'm also using TBZR to visualize the branch status.

The setup I'm using consists of one top level branch, with subbranches in some subdirectories. Each subdirectory, where a subbranch exists is on the ignore list of the parent branch to avoid conflicts:

+ project
  +- .bzr
  +- directory1
  +- subbranch1
  | +- .bzr
  | \- dir1
  +- subbranch2
  +- .bzrignore
  \- file1

project/.bzrignore:

./subbranch1
./subbranch2

The problem I'm seeing is that TortoiseBZR stops traversing the tree when it encounters an ignored directory not realising, that there may be a separate branch inside. This causes the overlay icons to be visible only on the toplevel branch, but not in the subbranches. The icons will eventually appear on elements of the subbranch when I enter the subdirectory and play with it for a while. There is however a lot of randomness in this behaviour. Forcing a cache cleanup when inside the directory also helps sometimes.