I propose including an Exchange Rate field in user settings. This would allow players to set the number of local currency units that equal 1 SMU, (default setting being 1-to-1). Then on the index scales simply multiply the existing value (now measured in SMU) by the local Exchange Rate to find the scale’s value in local currency. I would also add the option to view the scales in your local currency, if/when you’re viewing the stats of a foreign nationstate.
Example:
If NationA sets “2 ACoins equals 1 SMU”, then an index that currently equals 150 SMU would show as 300 ACoins instead.
If NationB sets “3 Bbucks equals 1 SMU”, then the same index value of 150 SMU for NationB would show up as 450 Bbucks.
I would add a sentence at end of the economic paragraph on each nation’s main page saying, “One (name of local currency) equals (Exchange Rate setting) Standard Monetary Unit(s).” Or vice versa.
EXTRA PLUS:
This info can also be used to calculate simple exchange rates between two countries by simply dividing the second nation’s exchange rate by the first nation’s exchange rate.