Hi @Gavin_Heale,
You’re on the correct path with your thinking above. The Home Hub frustratingly can’t Bridge, but there is a way to safely configure a partial DMZ on the Home Hub, but you’ll need to make sure everything is then connected to the downstream router (your Araknis, etc). Anything connected to the WiFi on the Home Hub will be in front of your security, so proceed carefully here:
Bell Home Hub - How to Set Up “Bridge Mode” by (Safely) Configuring Advanced DMZ
Please let me know if you have any questions.