Hi
It seems to me exchange rate is more a property of a single transaction rather than a property of a single date. Of course exchange rates should still be retrieved from a central authority, but it must be possible to deviate from them on a per transaction basis.
Accountants don't tend to do it that way. The idea is that you have a theoretical rate in effect on a given transaction, then if your actual rate beats that then you have an FX gain (or loss if not).
The breaks out the transaction at some mid rate, versus the gain/loss on actually having frictional costs in practice. (so if you transfer out of your Paypal account at the atrocious rate then this shows as a profit on the original transaction, plus an fx loss due to Paypal)
However, the UI is probably missing for all this right now and certainly in SL you just have to figure out all the bits yourself and type them in as a GL entry...
Also, a question from the user interface point of view: When I deposit a USD cheque into a CAD account, I will know from my deposit adjustment the exact CAD amount for that deposit. Currently with 1.2.x I have to manually calculate the effective exchange rate when entering the deposit because there is no way to say "I deposited $100USD which resulted in $96 CAD".
Again, the idea is that you deposited $100, which became $98CAD, less the bank skimmed you $2, which is your FX loss
The only thing missing really is a new data entry screen to put this lot in. The rest is just a case of ledger entries...
Ed W