In the Philippines, we only use "mestizo" not the other terms
So this is mestizo
all the way to this
As long as they're a Filipino with a noticeable amount of Caucasian admixture, we call them mestizo. The white ones used to call mestizos like the first guy "mestizo de entresuelo" as an insult. They were lower-class and they mixed with natives. The whitest ones like that guy ^ don't have much native Filipino ancestry. But I know he has at least a little because here are his dad (second to left) and relatives:
You can see some native features in these guys, but not in their son. So yes, I think you're right- Filipino blood dilutes easily in European ancestry.
He actually married a native-looking Filipino girl
Same with these Spanish-Filipino guys: