Unpopular opinion: is it maybe time to stay away from macro language altogether, and make the more powerful scripting languages easier to use for newbies, instead of implementing yet another workaround to the limitations of macros? 
Joking aside: I really like your pragmatic approach to build bridges for really everybody.
Ops currently have a few wrinkles that make them overly complicated, and almost impossible to use without any knowledge of ImgLib2 API. Maybe we can work as a community on improving the situation here? Also, there’s scijava-ops
around the corner, so the situation might improve soon.