Splatoon style game: How to get scale value from hitted splash material/actor?

BP Photos:
https://imgur.com/a/HYtw868

Video:
https://imgur.com/BWWaQJb

I’m looking for how to get scale value from that hitted decal.

Is there anyway to get scale and actual heights(like centimeters or feet) from decal Material? or should I have to make Actor?

One more question. Can I get only value besides overlapped Material too? I have to calculate percentage with color spreads.