It's ideal to have it as a unit of account, but to achieve a great application of this, it should be automated or understood that it's in "Satoshis". It's challenging if you're using BTC or mBTC, especially for those who are non-tech savvy or relatively new to crypto, but it's a learning curve.

Perhaps, if the technological infrastructure supports it, automation would suffice, and deductions for taxes purchased with it would be easy.