I have to tell you that I think the whole over paneling thing is a load of.....
Over paneling my MS controller heats it up considerably until it stops using all of the watts trying to protect itself. I have also read of a MS 15 on a larger GT panel stopped functioning for no reason. So I believe occasionally over paneling is one thing, planning on it regularly is another.
I haven't mounted my panels yet and have used them portable for years. The hassle of set up, adjusting, etc is minimal considering the near doubling of output. You will really notice it early on when a tracking panel is bringing you bank up at full output vs a flat that is barely awake.
There is a controller on ebay that looks a lot like the Eco-w in ways, the manual is very close as are the specs. The difference is it can be set to hold Ab time unlike the Eco-w. It is similar enough that I really thought it was the Eco-w upgrade but now I think they are making for them under a different name plate. Unfortunately I am in PV, Mx and don't have access to my links.