Though some testing I have gotten the brims to be either PETG or Support PLA. The brims come cleanly off the slug with out and sharp edges. 
This also incorporates the idea of the AMS for multicolored printing 

WARNING, even with this set up I have had slugs still come off the bed rarely. 
When Printing with PETG and PLA, make sure to use the textured or high temp bed and set both plastics to 60C.
Support PLA also can stick really well to the bed so print with caution