i've done installations of fortigate + fortiswitch, and also installations of fortigate + fortiap, but never all three
if i want to setup a flat lan for wired and wireless, how do i do that? because if i "box" the the fortilink port, and the virtual ports of the fortiap, i have no connection to the fortiswitch. only via fortilink physical switch i can use the fortiswich. but then, i can't join the wifi virtual port and i have to use it in a seperate subnet/interface
a flat lan for wired and wireless is a bad idea in my opinion. there is a reason that fortinet forces you to seperate networks for different things, that is a current best practice.
if you really don't want this then you can connect the fortiswitch and not use the managed mode, it will be regular switch then and you will have your APs in bridge mode on the interfaces towards the fortiswitch. but again, it would not do this.
The Fortinet Security Fabric brings together the concepts of convergence and consolidation to provide comprehensive cybersecurity protection for all users, devices, and applications and across all network edges.