No, rules just use manual interface order but SLAs are tied to interfaces. So when, for example, ping 8.8.8.8 fails through port15, it gets marked dead, static route is removed and traffic shifts to next preferred interface as per the preference order in the rule. But yeah it should work if you look at it but as others have pointed out, the global snat-route-change parameter may be of help. How this works in conjunction with SDWAN is a bit unclear however.
