K - why not have a run at diving the SW ?
I too stuck to one sub, the SW, for a long time. But converting to the Ak and sticking with her has given me new perspectives.
If I do return to the SW I will be armed with much more info about the Aks characteristics and performance limitations.
I will know much, if not all, of how the Ak diver thinks, how he employs tactics that match his sub etc.........
Give it a whirl - you will not be disloyal to your motherland as you learn the strengths and
weaknesses of the opposition platform.
The objectivity you achieve will improve your gameplay and could be good preparation for your eventual MP.
Match your practical skills to your knowledge base and the 'world's your oyster'