[GNC] User defined currencies in "Expense Accounts"

[Charles Crossan]

While doing my monthly ritual of breaking down my utility bill into
GNUcash, I had the idea of using a user defined currency for electricity
(Kilowatt Hours - kWh) and Water (gallons).  I'd like to be able to chart
my "real usage" as well as rate fluctuations.

I've been using GNUCash for over 10 years, and have created a bunch of
custom currencies for stocks / etc; however, this is the first time I
thought about using it for tracking utility units.

I got as far as creating the kWh currency when I realized that there's no
way to choose a "non ISO 4217" currency for expense accounts.

The GNUCash documentation seems to indicate that Income and Expense
accounts are only able to use "National Currencies" (12.2.1.1. User-Defined
Currencies -
https://www.gnucash.org/docs/v4/C/gnucash-guide/currency_manual.html
<https://www.gnucash.org/docs/v4/C/gnucash-guide/currency_manual.html>).

I'm wondering:

   1. Is there a functional reason for this requirement; or is it an
   arbitrary UI restriction?
   2. Would the application behave erratically if I were to manually edit
   the expense account in SQL to use my own currency?
   3. How is everyone else handling utility tracking?  I realize I'm
   probably a tad crazy for wanting this level of detail.

-- 
Thanks,