Just a heads up, nextcloud 13 (in beta now) will improve speeds by a large amount. No need to use nginx or anything else. If you need nginx, look into BSD, it offers a great jail system, or iocage whatever you prefer, look into setting up a jail in a VM and running nextcloud there if you need nginx. I am installing nextcloud 13 hopefully tonight after I “upgrade” my nas server (get rid of freenas, its turning into trash).