What do E/M/H buttons mean in contracts debug menu?

[GeneCash]

I'm trying to explore around Jool, but it won't give me a contract to explore Laythe or Vall.

So I ventured into the contracts tab in the debug menu. Under the "add" subtab there's various things like "ExploreBody" with "E", "M", and "H" buttons next to them. "H" seems to offer contracts I already have, and the E/M buttons just drop "[Error] Contract of type 'ExploreBody' was not to be generated" messages into the debug log.

I'm confused.

[Rhomphaia]

Supposed to be easy/medium/hard. I think it only determines the values for part testing contracts.