SD-WAN route lookup

Hello,

I'm having some difficulties understanding the route lookup process when SD-WAN is enabled.  According to Fortinet, SD-WAN rules (which are policy routes) are checked prior to FIB lookup. But, knowing there is always an implicit SD-WAN rule which catches all, will FIB lookup ever be performed for outbound traffic?

While researching, i came upon this article which confused me even more :)
https://docs.fortinet.com/document/fortigate/6.2.3/technical-tip-multiple-default-routes-where-sdwan-rules-are-not-preferred/20/fd47747

Thanks,

 Radu