I have already implemented a keyboard shortcut to invoke all tests and show the output even if it's hidden. This is very convenient if your tests run fast. If that's not the case (i.e. you have a huge Rails project), it'd be way more convenient to have the Guard pane hidden when the narrow-scoped test runs (i.e. only for one model) are successful, but to have it automatically shown when some tests do fail. This would require buffering the Guard output and analyzing the result, but I think it's worth the work.
I have already implemented a keyboard shortcut to invoke all tests and show the output even if it's hidden. This is very convenient if your tests run fast. If that's not the case (i.e. you have a huge Rails project), it'd be way more convenient to have the Guard pane hidden when the narrow-scoped test runs (i.e. only for one model) are successful, but to have it automatically shown when some tests do fail. This would require buffering the Guard output and analyzing the result, but I think it's worth the work.