The authorization model which is used by IAG should have the ability to specify ACR values which can be sent to the OP and used during authentication.
OP Support: Cloud Identity And ISAM
Want to request a specific ACR value on AZN redirect from the RP.
This can drive a specific Access policy flow on either ISAM or CI?
The ACR that is requested will be 'staticly' defined by the IAG instance,
or for step up scenarios, driven by authorisation policy.
Ie, to access this resource, you need this ACR value in your cred.
But other resources do not require it.