I think you're misunderstanding.
This isn't an effect I need to apply once, in one go, to a lot of clips.
I need to be applying this effect to many clips over the course of my editing, as I drag them into the timeline.
Some need the effect, some don't.
In order to paste the effect, I have to copy it first.
During the course of editing, I'm copying and pasting clips, sequences, etc. so I have to re-copy the effect for your idea to work.
That means finding a clip that has the effect, clicking the Motion tab, Command C.
Then find the clip I want to apply it to, Command V.
More work than typing in the scale.
I have a mix of clips in the timeline. Some need the effect, some don't.
I ought to be able to quickly call an effect preset to a selected clip with a keyboard shortcut. It's ludicrous that that isn't an option.
I could even find a third-party solution, if only there was a keyboard shortcut to apply a selected preset. But literally, the only way to utilize an effect preset is to click and then drag it across the screen. It's crazy!