Does anyone have a Schiit Yggy DAC?

I have no information about the Schiit YGGY DAC running hot and suggest you call Schiit, again, and and ask them.  k4rstar12 reported above that "he owned multiple YGGY's and they were never more than slightly warm to the touch even after being on for many weeks".   I suggest you determine how hot your YGGY is actually getting so you can review its actual temperature with Schiit.

Please note that my Ayre Codex DAC also ran hot.  The Stereophile review reported "My sample of the Codex DAC got hot to the touch—about 108°—after a couple hours.  HiFiPlus reported "Almost – it runs hot to touch like an Ayre amplifier (nothing to worry about here).   Ayre reports the Ayre’s exclusive Diamond output circuit run hot and this is normal and nothing to worry about.   I kept my Ayre Codex DAC on all the time and it was hot when being played and was never a problem.   

Just measured the temp on the top plate of my Yggdrasil and mine is at 82F at its hottest in a room at 67 degrees. Sits on a shelf in an IKEA Besta unit with about 4 inches above and 3 on a side for breathing space. 

82F is reasonable temp. for a DAC, I don't see any problem here.

Exactly. My Mytek Brooklyn definitely ran hotter.

The Bifrost multibit was a cold fish, even the Mimby was a fair bit warmer.

 My Gungnir is moderately warm only, but it is quite sweet.  Speaking of food, I prefer a slightly sweet chili and put sugar in my coffee, so the sweet Gungnir comment could be off base.