Transfer between Bank Accounts when both are a Foreign Currency

Continuing the discussion from Bank tagging rules (Bank transfer between accounts):

When transferring between two Bank accounts that are not in Sterling by using the obvious method of doing a transfer from Euro Account 1 to Euro Account 2 the exchange rate is calculated by xe.com; however this has a problem!

Account 1 Euro has had the sterling value calculated from the payment already calculated on a different exchange rate to xe.com; and so if processing these bank transfers by the obvious method then the receiving Euro Account 2 does not balance with the originating Euro Account 1.

At present the work round that keeps the accounts inline;

  1. Bank transfer to a “Sterling” account
  2. Go to Chart of Accounts - “Sterling” account that has received the bank transfer
  3. And use “Move to new code” to transfer to Euro Account 2

By using this work round the two Euro accounts are balanced with each other.

What I would like as feature is the ability to set what the excahnge rate on foreign bank transfers i.e. a box to set the “Sterling” value between the two accounts.