Alyssa Yorgan wrote:
...I often find myself wishing I had a detailed explanation for what a certain function does.
... don't get me started.
what units are removed exactly? The earlier of two (or more) units with differing target translations?
The older ones. However, you can usually avoid this by fine-tuning the settings of the TMs. In case of your "Big Mama", you'd want to keep all TUs, whereas you'd only want to keep the most recent ones in the ProjectTM. See here for more on the subject.