Roulette Hot vs Cold / Gambler's Fallacy proven a "fallacy" yet again

I partially agree with you but I've to clarify a few things, his progression is not Martingale, you can call it as 7 spins parlay.
He counts on clusters, when you win on a number you get 35 units net, divide 35 by 7 spins and you get 5 units bet per spin.
In other words, before a number hits for 2,3,4,5...etc times, it'll hit once, thus you don't need to know what happened x spins back, just bet every number as it hits.
Therefore you won't lose by numbers which won't show for x number of spins, also you will win on any number which will hit twice or more.
The only problem are the average numbers which hit just once and then disappear, if the parlay after a hit is 5fold it means that you expect another hit within the next 7 spins (5x7=35), if the parlay was 4fold it would mean that you expect one more win within 9 spins (4x9=36), if parlaying 3fold then you are extending the parlay up to 12 spins (3x12=spins) and so on...
I've tested the 5fold parlay but the results were poor because sometimes you have to wait for more than 500 spins before you recoup with a clustered number hitting 5 times within 35 spins.
The drawdown was gentle but it was a terrible waste of time, in my point of view a 3fold parlay with 12 spins window would be much more practical and realistic, smaller gains but more frequent.
You could even try the doubling up parlay for 18 spins, just keep in mind that you don't have to parlay if you are winning with flat bets, parlay is being activated when there is a drawdown in regards with your last bankroll high.