N.B. I have not assessed the behave DSL against the potential problems noted below.
It looks like the behave framework is yet another Domain Specific Language (DSL).
The important questions relate to the advantages and disadvantages of a DSL versus a
library (containing the same functionality) written in a
standard language. For the AD2, JavaScript would be a suitable language, since that is already available in the AD2 Waveforms software.
With a DSL you have to consider training someone to use the DSL, and that might mean creating training material. You can't just hire somebody off the street with the specific experience. With a DSL there are no toolsets, especially context sensitive editors and debuggers. With most of the DSLs I've seen, the interaction between language features is poor. As time goes on and deficiencies are found, more features are added, and the result can end up as an unholy mess.
Using a standard language avoids those problems. With a halfway decent library, it is just as easy for a non-technical person to create simple "scripts" which just call the library functions.
So, while there can be valid uses for DSLs, IMNSHO usually libraries in standard languages are preferable.
If I was to use the AD2/Waveforms as a test platform (which is very tempting), I would investigate JavaScript first. I would only move onto a DSL once I found things that couldn't be done.
Background snipe: all hardware engineers dream of creating a processor. The software engineers' equivalent is creating a language+compiler