The stock repair strategy is been around ofr a long time and is simply adding a call ratio spread to a stock position. Does it lower your breakeven point? Yes. But it does not fix a losing stock position if the underlying does not cooperate. I have taught the stock repair strategy as well but told people it is a tool and applicable in a limited situation where you buy a stock and it drops and you expect it to recover somewhat but maybe not back to where you bought it at. If you perceive no further significant drop than it is a tool that can be used. But it does not repair a broken position if your initial extimate for the underlying turns out to be wrong completely. Then just cut your loss.
I hardly ever double down (learned from experience). Also I keep less that 2.5% in my stock portfolio, in any one stock. Mutual funds and things like QQQ/Apple would be exclusions...
It is not really a double down as it does not require additional capital. It simply adjusts the breakeven point assuming your underlying analysis of the stock has not chsnged or you are not ignoring an obvious signal your analysis is now wrong.