The account_balance and send RPCs are heavily used by the faucet. We have some conversion functions for mrai/krai/rai to and from but I agree, we probably want to minimize that because it's confusing.
In the next release I'm going to make it selectable and probably default on krai.
I saw your solid background on Linkedin.
May I ask. are you working full time on this project? I bet not.
then what is your plan or vision for Raiblock? one thing is impressive is that You have developed it for 2 years.