Hi @cholmes Sorry, I'm already home (its 9:30 here). Its great to hear you managed to get it to run, good job! I inspected the SanFranciscoS2BGRN.tif case. Theres two things: 1) The default contrast correction is way off as the image seems to be in a good contrast already by itself. I'm working on this issue (as it currently affects all RGB images). 2) if this image originates from Sentinel 2, then bands are a bit odd. In the gdalinfo it displays the band description as B2, B3, B4, B5 (which is actually Blue, Green, Red and Near Infrared) so the colors are quite odd indeed. The second image has the same contrast issue. If you click on the wrench in the upper right and delete the 'sigmoidal' step, then the image should be quite normal. The default settings originate from a version where we thought only Landsat 8 images will be displayed.
Forgot to reply here, but thanks! Things seem to be working really now. I'm definitely going to talk this up a lot at foss4g-na, and I think a lot of people are going to be blown away.
Also I think will aim to do a medium post that features it some. Also need to announce my cog-map + tiles.rdnt.io service we're standing up (marblecutter lambda tiler for cogs).