MQTT with different topics

[dziban303]

With the new MQTT broker built-in I thought I'd be able to attach MQTT connections to brokers in other regions which use different root topics; my local mesh uses our own mqtt server and msh/US/LA as the root topic. But I'd like to connect to the Houston mesh which is using the meshtastic public mqtt server with the root topic msh/US/TX.

So naively I thought if I set up the built-in broker and the nodes to just use msh as the root topic, and then set up the MQTT bridges with the appropriate topic (msh/US/LA for my local, msh/US/TX for the Houston mesh), it'd Just Work™ but that hasn't panned out.

Can someone tell me what combination of root topics (broker, bridges, and nodes) I'd need to configure in order to send and receive mqtt messages on different root topics?