Whichever solution you pick for the "test" issue, I would at least add a code comment explaining that the test return value needs to be garbage collected and why, etc. and probably reference this issue.

> If anyone thinks the 'ReapedSuite' class (or a better named copy) could be useful elsewhere,

Can you look at some of the other test modules' test_main() functions to see if the same pattern is used there (or look at other uses of reap_children(), etc)?  Then we would know what would be useful elsewhere.