Anvil app server: moving location of /_/

Is there any way to specify an alternative location for the // path? The reason is I’d like to reverse proxy (using Nginx) multiple application servers. I have a reverse proxy working with one app server already, but the problem is I can’t have a single // path for two reverse proxies.

P.S. I’ve tried using the --origin parameter, but it has no effect on where calls to /_/ go.

Thanks,
Ken