Some OAuth2 providers do not work with the redirect_uri being sent

The OAuth2 redirect_uri is an optional parameter - see https://tools.ietf.org/html/rfc6749#section-4.1.1
I have added a new SendRedirectUrl property (defaulting to true for compatibility) that allows turning off   sending the redirect_uri parameter in the authorization request. The reason for this is that I am trying to integrate with a provider that returns 400 if this parameter is supplied as they mandate that the only URI used is the oine set in their developer dashboard.
Obviously naming of the property is subjective so could be changed, but hopefully you can see what I'm trying to achieve.