This is my preferred option but it's only available for US accounts. See the banner under the documentation here: https://stripe.com/docs/connect/add-and-pay-out-guide?integr...

I reached out to Stripe support to confirm and this was their response:

Cross-border payouts are only available in the US for Platforms.

All connected accounts in every supported country can receive payouts, Connect is the only option there is with regards to transferring funds from one account to another.

So cross border is sending payouts to connected accounts in different countries. If you are in the UK and your connected accounts are UK based, then there would be no issue with payouts to the connected accounts