Not at all... I find that eminently logical.
Forcing Doug and Tony to (1) explain their bizarre garb with each shift; and/or (2) to find appropriate clothing would have taken considerable time from the main plot.
I thought about that, but if they'd've eliminated the repetition of the previous episode's set up, that could have added several minutes to each episode. They could have turned it into a running gag. After a while they would have become proficient at it (as Sam on Quantum Leap eventually became more proficient at learning into whose body he had leapt), and less time would have been necessary to devote to that aspect of the plot.
I like the “reversion theory” (or whatever you want to call it). My viewing schedule is a day ahead of Bob’s discussion schedule, so I’ve already seen “End of the World.” Tomorrow I was going to speculate that either Tracy’s theory is correct and even so small a thing as coal dust cannot be transported out of its own time, or the Time Tunnel also launders their clothes. (In a way, I guess, it does.) Unless their perspiration is of the era in which it was secreted, I would assume it’s 1968 sweat. They were pretty filthy after their time in the mine yet spic ‘n’ span after their next trip, so the revision theory must be correct.
I like that there trips occasionally take them into the future. I didn’t much like that in Quantum Leap Sam Beckett was supposed to be able to jump between points in his own life time, yet never (well, seldom) travelled to the future. (Actually, I think he did once later in the series.) Maybe he didn't live that long after he stopped leaping. Granted, the underlying premise was that some “force” was controlling the leaps and he needed the help and knowledge of the future in order to change the past, but just once I would have liked to have heard Al say, “Gee, Sam, I have no idea. You’re on your own!”