Assigning a customer to a specific worker:
If you have a customer that you want to partner with a specific worker, you will need to load balance them prior to the customer purchasing. To do this, go to the Sales Split box on that service > set that worker to 100 > set any other workers to 0 > save. Then, the customer can purchase and you can load balance back afterwards, should you want.
Changing the worker for a customer post-purchase:
You can load-balance to a specific worker pre-purchase. You cannot switch the worker after a customer has purchased. Should you want to change the worker post-purchase, you will need to cancel & refund the customer's purchased gig > load balance to the worker you want (see above) > and then have the customer repurchase.