Better to wait for 1.4-rc1, I added some minor things and checks that help this case.
There are still 2 issues with it, which I think are minor (and this is all experimental/testing anyway):
1 - pedalboard thumbnails don't show connections from/to slave ports
2 - when loading netmanager after the mod has been started (ie, running jackd after the mod boots), the gui might show some connections which have not truly been made yet. Reloading the current pedalboard fixes it.
Because this is still being experimented with, those 2 small issues will remain.
Things are already usable in 1.4 as it is.
(I'll let everyone know how to enable this on its official release post)