I’d advise you to simply send in a letter about that, as episodes focused only on RPG mechanics don’t seem very popular, honestly, and I don’t think that that single topic would fill up an entire episode.
As for the problem itself — besides the obvious solutions of not awarding Collections anymore, capping the number of Collections Heroes can use per issue, or ramping up the opposition — one possible solution could be giving Villains their own Collections. (Either an arbitrary number or an amount actually based on their number of appearances, although the latter method would likely result in a very small number of Villain Collections, unless you have an extremely prolific Villain such as Baron Blade.)
Another possibility is saying that heroes can’t use all their Collections on the same type of benefit. Collections can be used to manipulate dice results, add a fact to the scene, or negate a Minor Twist — a GM could say, for example, that Heroes can only use half their Collections to do any one of those things every issue. (E.g., a Hero with 6 Collections could only use 3 of them per issue to manipulate dice results.)