Hi all,

I've been working on building in support for cartopy projections for geographic data in yt. My PR for this work is here: 


I've submitted the PR to be merged into master, but I wanted to get some advice from you all if this should be changed to yt-4.0. It adds in some newer functionality that's not directly targeted for the yt 3.5 release. Another option could be to submit it to master but merge after the 3.5 release. Do you all have any advice or preference on where this should go or what the process should be here?