Well, I do feel stupid now (about trying to use the result of .parse). On the other hand, this shows what many years of writing Clojure and ClojureScript does to you: it didn’t even cross my mind that you had to hold on to sm-consumer and return that 
Anyway — this is exactly what I ended up using and it works fine. I can get at least some information out of the stacktraces, which makes them much more useful. And it’s such an easy win once you have client-side logging implemented — the .map file usually even sits right there in resources, so it’s easily accessible by just calling io/resource.
Thank you for your help!