I know the tag arena in Bree has a special area and special rules. I don't know what the effect would be on system performance, but I CAN see that enabling this for a much larger area could increase the strain on servers, causing yet more lag. I think it is wise to stay away from these types of things until the SSG team has a (MUCH) better handle on lag.
Moved from Riddermark to Arkenstone on 9/29/2015!
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Disclaimer: The definition of "Soon™" and "In The Near Future™" is based solely on SSG's interpretation of the words, and all similarities with dictionary definitions of the word "Soon™", "Near", and "Future" are purely coincidental and should not be interpreted as a time frame that will come to pass within a reasonable amount of time.