Activator performance improvement

Shouldn't close the previous PR early. Turns out I did not have to change much of my design.

Pinging previous trackers
@pranavkm
@halter73 
@rynowak
@ipjohnson
@yishaigalatzer 
I was a little bit on the fence about this. Do I want to permanently hold on to this object to save a little on expression compile time which only happens once per serviceType?

Should we keep it simple until the profiles tell us to do otherwise or do you think it is worth it to start with that?