[AlexanderHowl]

One way to deal with scaling is during using the Extra Effort (including Godlike Extra Effort) rules from Powers (p. 160-161). Of course, the penalty for Extra Effort is rather steep, so I would suggest creating the advantage of Grit.

Grit [5/level]
-Grit reduces the penalty for using Extra Effort (including Godlike Extra Effort) by two per level (maximum 10 levels).
-[I]Special Modifiers[I]: One Source (Grit only applies to the abilities from one source and does not apply to other uses of Extra Effort, -20%), One Power (Grit only applies to the abilities from one power and does not apply to other uses of Extra Effort, -40%), One Ability (Grit only applies to one ability and does not apply to other uses of Extra Effort).

A character with Grit 10 could then attempt a +100% Extra Effort roll at no penalty. While it might seem cinematic, we have plenty of examples of people throughout history who have driven themselves far beyond human endurance without evidencing any other exceptionally high traits, so it is likely appropriate for any setting that allows Extra Effort. It is especially appropriate for supers settings and any other settings that use Godlike Extra Effort.

How does this compare to the suggested ability? In settings that use Godlike Extra Effort, Grit 10 would allow characters to directly scale their ability level by spending more ER/FP/HP (for characters without ER/FP). The advantage of this over a scaling advantage is that it is more limited though it is cheaper.