I'm not sure of all the specifics that cause the issue, but when I set the gutter parameter in
add_region to an empty string instead of the gutter icon, BH no longer brings down ST. It's possible there are more variables that need to be aligned just so before the gutter can cause the issue, but removing the gutter icons fixes the issue with BH for me. Before, ST would be brought down as soon as BH performed a match, but now it seems to have no issues.
Keep in mind, I spent only enough time to identify how to keep from failing, I haven't explored whether there is a combination of settings that need align to cause this.