Sorry for the slow reply.
Long story short: entity resolution on emails is a very thorny problem, and there are many techniques we might use to solve it.
If I recall correctly, I wound up building my own entity resolver for performance reasons. Your (awesome) entity resolution requires an n^2 Levenstein distance matrix which was prohibitively expensive for some longer lists (and combinations of lists, which is what I've spent some time looking at).
I've made a new ticket for consolidating the various entity resolution scripts into a single module that documents their differences.
I suggest we move any further discussion of this issue to that ticket. There are also I believe some existing tickets on this to be linked there.
- Seb