I think the answer is no as I don't see steps to configure this in the SNR guide, but are you able to set time periods that SNR is enabled and disabled automatically? If the answer is no, is that a road map item ?
Not a big deal- just asking for a customer.
As you suspect, this is not supported. It is only ON and OFF. As per today you can use the UCC Mobility Server option for having advanced SNR functionality.