Seems a bit silly to have 16 bit tiffs supported but not EXR's. I would prefer to use EXR because I can embed an alpha channel and the compression is much more efficient than anything when it comes to alpha channel and solid colors. (when scanning objects im creating masks in nuke and also filling the masked areas black. I was testing file sizes and my EXR's were roughly 10 times smaller file size with same bit depth.
Thanks keep it up!