Now the currency is set in Deal Pipeline settings and is the same for every deal in the pipeline.

Our deals are in different currencies, EUR, USD, etc. depending on the customer's location and I need to have a possibility to set a custom currency for every single deal separately; otherwise, it's not usable - I either need to create a separate pipeline for each currency, which is not ok, or make currency conversions when I add a deal if a currency different from the default one.