Best Practices / Recommendations for Watchguard Appliances in relation to Office 365

D20

Microsoft recommends, essentially, that all traffic for Office 365 be excluded from the very types of things most security appliances and firewalls are intended for in order to have an 'optimum experience'. That being said, coupled with the constant update/fluctuation of Office 365 IPs / Endpoints, what are some of the easiest ways for a WG appliance (in my case M500) to honor the Microsoft recommendations without have to constantly babysit the aforementioned Office 365 IPs / Endpoints? What have others done here in this regard? I'd be very interested to hear.