bosses 😞
1. yours coworkers will see kotlin anyway in test etc. so they have to know kotlin as good as it would be on production
2. If I ware you I would try to come your boss around to use kotlin. Maybo some presentations, internal workshops?
I am using Kotlin in 3 production apps and one lib:)
Anyway your idea may works:) unit test in java and junit is a nightmare and in kotlin its looks pretty nice. What would you like to place in 'internalDebug' ? mocks/stubs etc?