An efficient way to get the name / MT of ValueTypes not listed in! Dumpheap -stat

I am working on SOS commands and their outputs, but I noticed that there seems to be no way to get really all the types that are currently in use. The best way so far is !dumpheap -stat, but it only displays types for which there are instances. However, when a ValueType is never placed in a box, this type will not be displayed on !dumpheap -stat. (Which is not surprising, since they are not distributed over the heap.)

So my question is: Are there any effective ways to determine which additional ValueTypes currently exist? I mean, I could load them on demand when checking individual heap objects (something like !dumpvc <mt> <address>based on the output !do <address>), but for the displayed statistics it would be nice to find types using simpler means than viewing (instances / class) all known classes to find out if they use any additional ValueTypes.