Jill, One way that I have found to keep track of specific matches is to give them a yellow favourite star, then there aren't as many to go through. I try to use this only when a match has been confirmed though.
Another way - in your notes make a comment on surnames in their tree, search for that surname and hopefully they will come up.
Today I saw something different, only works if you have sent them a message. A search by username in messages.
Another way, a bit longer, but should be quicker than your current method - search member directory for username - not always successful.
Final suggestion, would need updating over the months and years - in your notes make a note of what page the match is on, use Find in Page for username.
Regards Margaret