What you are trying to do is a common need that would warrant a nice tutorial.
I have not tried it yet.
If I were you, I would go though the available options shown at https://github.com/lxc/lxd/blob/master/doc/containers.md
Specifically, I would also do a quick try with a bridge instead of macvlan.
An alternative would be to create the macvlan interfaces for that network card on the host, and then configure the containers to use those macvlan interfaces. See the discussion at Multiple LXD containers on single macvlan interface
See https://hicu.be/bridge-vs-macvlan for an explanation of different modes.