In GH you can make an extra house. I assume you can transfer those lights to that house. For recognition you could give these lights a name with the name off this second house in it.
Then you can, in theory, rename your current home, create a new one with the ‘old’ name, and move the couple of zigbee devices to it.
Then most of your devices are in the other home.
I think there’s one down side to that, all new Homey devices from now on, probably end up in the original, but now “old”, Ghome.
Up side: new devices won’t ‘litter’ your ‘new’ Ghome.