An option to choose non-business hours in SLA Policy would help a lot.
We have IT/Business Services wich may have different operational hours (Support hours). e.g. MOFR05-21/SA05-14
We are not able to stop SLA timer, when we have ticket where these services are affected.
To assign Non-business hours to the Group solve not this situation, because we have all teams working during default Business Hours and they need to become these tickets to fix it.
Another solution would be to connect SLA Policy with IT Services from Asset management (CMDB)