The only issue there is that the RAP3 won't be able to do a mesh connection since those only support 2.4Ghz and the mesh link is built using the 5Ghz band .
You can potentially try having an IAP105(Virtual Controller) configured the wired profile as an uplink and connect it to one of ports of the RAP3 and that IAP105 will make the mesh connection back to the other IAP105.
Hope it make sense