webDAT JSON cook time

The webDAT appears to take significantly longer when fetching JSON than XML. Despite being in asynchronous fetch mode it does some really long cook times at the end of its fetch(40ms in my case) whereas it won’t do this with the same dataset formatted as xml. Even having the viewer on of the webDAT containing the JSON response kills my system. Middle clicking for info just fils my screen with the contents rather than the “…” at the end like with the xml webDAT.
The web dev mentioned that he’s enabled the compression after reading about its support on the wiki, could this be what’s slowing the JSON webDAT at the end of its retrieval?
At this point JSON parsing seems a lot faster than the XML dat, it’s just the webDAT diference that seems to be slowing it down.
v.25000

Do you have example datasets we could use to reproduce this issue? and/or a .toe file?