Customer Property:

if you have a look at qtc customer properties you will see this:
WEB_BOOKING_CONFIRM_EMAIL_TEMPLATE_resource_2c9081456937933a016937e4f83f000f
This allows a specific email template (id) to be used as the booking confirmation email
2c9081456937933a016937e4f83f000f is the court id in the database (which is Clay court 21).
QTC has several clay courts so if they want clay courts to have a different confirmation email then you just need to do this for all clay court ids.
The value to put in is the email template id.
But it looks like they don’t even use a template for booking confirmation email. So you may want to “educate” Adrian on his one and make good use of it.