Just use the US LLC’s bank account and an EMI or something. All legal. I don’t see the need to do anything else if he can legally be tax free for 4 years.
You can use a UK LLP instead of the LLC. They are basically the same thing just UK is a better jurisdiction.
You can remit the funds you need to pay plus whatever you need until your ready to move.
As @Tax Cow said slowly reduce the funds in Morocco.