Adding new product to an existing order uses default price (no conversion)

On the frontend side this plugin does its job on an excellent level for me.
On the Admin side, I have two issues:
1) I can’t create new orders in (or switch any existing orders to) different currency. According to Google this is a know behavior of this plugin. Not the best, but I can live with it.
2) My bigger problem is that if I have an order placed in GBP, and then later I’d like to add a new product to it, then the new item is going to have EUR price without conversion.
Example:
Test Product = 100 EUR.
If I add it to a GBP order as Item 2, it will be shown as 100 GBP.
Item 1 on the same order is converted correctly from EUR to GBP, using 0.883 conversion rate.