We have a number shipping methods now and need to add more shipping methods for a seperate customer base.
Each customer type is defined by role.

In summary we need
Shipping methods that are only available to our retail customers
Shipping methods that are only available to our wholesale customers

Each customer type will only need to see their appicable shipping rates.

I realise we can do this using custom rules but we are looking for a simpler method as we would prefer not to have to rewrite all of our existing retail customer shipping methods.

It would be ideal if the Role Option could be added to the Shipping Method Availability Basic Rule. It would need to enable or disable certain roles. This would work the same as the Regions selection.

Please advise you thoughts

Thank you