What is the "unit of account" in terms of Bitcoin? Traditional economics depend on a "unit of account".  Can anyone explain how a "unit of account" would be manifested in Bitcoin if so desired?
The "unit of account" is "what all your numbers are denominated in".

For instance you might work day-to-day in dollars/ pounds and yen but your unit of account may be dollars. Everything would get totalled up in terms of "dollar equivalents" and you would typically report in dollars.

You can choose whatever unit of account is convenient to you.
The obvious one to use is simply bitcoin. You have all your accounts in bitcoin and report in bitcoin.

However you may have to report yearly accounts to (in the UK) Companies House who want to see reports denominated in pounds. Say because of this you decide to have your unit of account to be pounds.

Thus you need a rule for converting your bitcoin to your unit of account, pounds. Perhaps you choose a daily conversion rate and convert all bitcoin received that day to pounds. (Or you might use another conversion algorithm).

Your unit of account is what you measure your money in.
It is a bit like measuring distance in centimetres or inches or light years. Choose the unit of account to be the easiest for what you are trying to achieve.