Thanks for the excellent suggestions.
The address suggestion is neat. It can help break away from the sig: prefixed construction. I’ll have to see how we can translate that into plain Script usage, e.g. in situations where we do things like script_sig: 'sig:@alice ""', etc.
Writing features.py with this DSL will be a neat way to validate the expressiveness of the DSL, so I’ll try to do that. I do want to say that the goals of features.py and this DSL are slightly different. The goal here is to write contracts and system state transitions at a high level to facilitate clearer communication between developers and to quickly experiment with ideas.
reorg_chain is interesting idea too. I’ll definitely incorporate it. I have taken a slightly different approach until now and that is to reset the system state to run a different set of transitions, but I can see some situations and developers will benefit from a reorg_chain approach.