The stuff with saving conversion rate and getting a credit is somewhat dodgy. F42 has no income so who pays for the rates in which currency?
I would imagine this isnt an issue.
I can give you any currency to help you run your UK business or even a large consignment of frozen space chickens. At some point you are going to want to convert the currency I gave you into local currency to pay your costs of running the business (or sell the chickens!)
Alternatively if i know you are operating in the UK, I can give you Sterling and then you already have Sterling and dont need to convert it to pay your business expenses.
What we decide to do to fund your UK business would be a matter of weighing up the relative costs and benefits