I took the testing to mean (perhaps incorrectly), testing your objects compile etc, which is something Ive personally wanted to do away from an axoloti.
but yeah, full patch testing, as you say thats more likely to be fulfilled by making the UI be able to create VSTs or something BUT... to do that we also would need to take out/substitute the arm code from the objects, as well as adapt firmware calls etc.
brief discussion here on this topic
(I guess you could use an arm emulator, but frankly as much effort as doing a VST generator and not as useful
)
so yeah, Id guess that would be outside of 'axoloti' , but a great open source development project.