So I've made a couple of industrial themed machines, which use some custom blocks like 'External Motor' and 'Gearbox'
And I'm using a recipe-modifier to upgrade ("overclock") the machine, by putting in a better motor/gearbox.

Right now I define the modifiers like so- https://pastebin.com/xMWJ7wvY
Which works at the technical level, but also allows for undesired machine combinations involving two motors or two gearboxes.

Is there a way to define the modifier such that both a motor gearbox can be set into specific positions to unlock the modifier?

Running Modular Machinery 1.9.5, and Forge 14.23.5.2779

So that it requires both parts in order for the modifier to apply?

I'd like this too, by connecting the "modifier" definition to a "parts" definition. So you have essentially a multiblock definition, then a modifier definition to go along if the secondary multiblock is completed.