We must provide a static tax rate to the customer who chooses a specific method (Local Collection). This tax rate would not be based on a customer zone and would replace the zone rates that might exist.
I can get the shipping method from the order and create a new TaxRate object, but I do not know how to integrate the system to force this tax rate when the shipping mode is selected.
I've tried to return the TaxRate object from a custom TaxResolver (extended from TaxRateResolverInterface), but it does not set tax rates for the customer.
Any ideas on how / where to force the application of this tax rate?