I have had such enthusiastic feedback from granting people access to the ~full dataset. They have been conditioned to expect whatever subset can fit inside an email or a powerpoint slide. I feel a little embarrassed when people fawn over the utility because it is so easy to get running.
Have not yet had a chance to try the idea, but I am toying with using render-images to bake in pre-built plots + markdown for reporting the output. Queryable report in a file. Dynamic Vega plotting (RShiny-ish) is also in the back of my mind, but that feels too close to magic.
It is an incredibly useful tool, and I appreciate the workflows you have enabled.
https://datasette.io/plugins/datasette-saved-queries is the plugin for storing queries - it's pretty basic, there's lots of scope for improving the story around that.