Imagine for a moment that Bitcoin transactions were locked into a particular fork and could not be migrated. Under this situation active stake is similar to the “average Bitcoin days destroyed” metric.
I did not understand this. An explanation of “average Bitcoin days destroyed” would be useful (google produced only this article), as well as what you mean by the first sentence. The language is ambiguous. By "locked in" aren't you referring to confirmation of the majority fork? By "migration" do you mean the minority fork?
OK, I'll admit this a nit: DPOS - the "O" = of, and is upper case and it is lower case in TaPoS. Consistency helps clarity.