The whole macvlan containers not being able to talk to the host has been bothering me, so I dug into it a bit. You’re on the right track with this post: Host to Container connection with macvlan bridge
The correct solution is to figure out how to get your host to talk to the macvlan container. You already found the old solution provided here: http://noyaudolive.net/2012/05/09/lxc-and-macvlan-host-to-guest-connection/
Another possibility is to move your primary host interface to a bridge and then use that same bridge for your containers, as described here:
https://blog.ubuntu.com/2015/11/10/converting-eth0-to-br0-and-getting-all-your-lxc-or-lxd-onto-your-lan
Both of those links are pretty old, at this point, so there might be a better way to do this altogether (also depending on what version of lxd you’re using). I’ve used netplan a little, but not enough to advise you on how to implement either of these or other more sophisticated setups, but if you figure it out, can you post the solution to Host to Container connection with macvlan bridge ? Thanks