Hmm... As indicated, implausible matches can be ignored during manual profile creation. However, they cannot be ignored during a gedcom upload (at least I couldn't find a way to ignore them in the small number of gedcom uploads I've done). This already results in creation of too many Rejected Matches between people who don't look remotely similar, but happen to have common names.
Is there any way to avoid having to create excess Rejected Matches during Gedcom uploads?