I'm pretty finicky about my time travel. If you don't "get it right", I snark, and snark hard.
Our review from Timelinks (see me profile):
Frank Parker travels back in time, and phones in to the Project: "This is Conundrum". You got that right. He should be at the office every time he calls in, but no, he's just not there. Shouldn't we be facing a Frank Parker glut as elder Franks arrive to fix problems and hang around with juniors who have no need to go back and fix any problems?
Dave Fooden's theory: Every time Frank phones in, the Project offs the Frank at the base. Must be a meadow somewhere stuffed with bodies of extra Franks...