Option to have pinned language pairings

I’m a native English speaker but I’m finding it tremendously helpful to learn French with the first language set to Japanese, and to learn Japanese with the first language set to French. I’m at an advanced level in both so I find this is a good way to use both languages creatively while also cutting out my instincts to think in English.

Is there a way to implement a setting so set when a user selects one of their active languages, the first language switches to the default for that active language? Right now I select one of the two target languages, and then adjust the first language to be the other.

Just an idea that would make my experience marginally easier. If this would cause more problems or result in unnecessary complexity or interface clutter, I completely understand too.