How should non-standard mapping directions be handled?

Common mappings are: `obfuscated -> clean`

But what if the mappings are `clean -> obfuscated`?

Or if they're like TinyV2 and have `obfuscated -> intermediate -> clean`?

How should the UI and mapping implementations be modified to allow all of these capabilities without being overly complex?

Idea: In the Mapping main menu, have a sub-menu at the bottom for inversed mappings. They will be read in standard order then inverted after being populated. This addresses the inverted direction, but not Tiny2 with its intermediate.