Putting DD-WRT VPN router in front of Orbi RBR750 Mesh in AP Mode

[watkincm1]

I replaced my older Linksys WRT1900AC with a new Orbi RBR750 Mesh router and satellites (2).  This Mesh system provides fabulous bandwith across my entire "campus".  

However, the Orbi doesn't support VPN as a router so for VPN access, I need VPN clients everywhere that constantly inhibit access to other devices within my LAN like NAS boxes, security hubs, etc..

It turns out my old Linksys is DD-WRT compatible and could be converted to a dedicated VPN router, placing it between the Orbi and my LB1120 modem, setting the RBR750 Mesh router to AP mode.

Has anyone done this?  Are there any gotchas in there or suggested configuration settings?

[FURRYe38]

When in AP mode the Orbi system is just that a AP wifi access only system. The Orbi system will do no routing or VPN. 

Something to inquire about over in the Linksys or DD-WRT support forums regarding there product.