It’s pretty funny that I was looking for the same feature for pretty much the same exact reason one day later. I also analyze a lot of analytical chemistry data (environmental, in my case) and would love to see this be possible, in the future at least. I’m interested in applications like this https://onlinelibrary.wiley.com/doi/abs/10.1111/j.0006-341X.2001.00022.x.
Is there a STAN issue or something which I can track? Or is this one of those structural things that is unlikely to ever be possible?