@silkster365 wrote:
I’m reluctant to start changing the whole network topology
The other way of looking at moving the routing to the Deco now, is that it will be good preparation and future-proofing for when FTTP becomes available to you in the next three years, as your upgrade will literally be unplug the ethernet cable from the Plusnet router (in bridge mode) and plug that same cable directly in to the new Openreach FTTP ONT, with no other configuration changes needed, job done !