@ogra I saw you commented on this topic in another thread Accessing /tmp from snaps? - #15 by quattrolinux. I will appreciate if you bring your insights into this thread 
You chose a phrase something along “so snaps cant steal data from other application”. The issue is that some of the files that traditional non-snap apps save to /tmp, are meant for other apps to read. Maybe not steal, but indeed read
In my case, a build script writes the test report to /tmp, and the intention is that it can be opened by a browser. Would you say that the authors of the build script have misunderstood the conventions by saving such a file to that location? Or have conventions just changed (at least on Ubuntu) now that Snap has become the default way for installing a browser on Ubuntu?