Looking to install mesh - use existing setup or buy a new router?

My current setup is a Virgin Hub4 (1gig) set to modem mode + Linksys WRT32x flashed with OpenWRT + Virgin wifi extenders. Still experiencing a lot of lag issues with things like Teams in certain areas of the house so was considering installing Mesh.

My first (non OpenWRT) option is to purchase a Netgear XRM570 router + mesh extender unit. Gets good reviews. Nice and simple, Use the stock firmware and off you go. But I like OpenWRT so my other option is a decent mesh system (albeit around the £250 mark). Idea is I would either disable the routers wifi and plug the Mesh into a 1gig ethernet port. (Might even rename the SSID on the router and hide it so it is there if required)

Anyway I quite like the look of the Linksys WHW0303 Velop. But when you read the setup it infers that it must have its own IP range to the router it is plugged in to, 10.x.x.x I think and you cant change it. So that would mean issues with any hard wired devices on my 192.168.0.x range I have (including printer),

Has anyone got Mesh setup with the same Ip range as the router it is plugged in to? I am assuming some will do that (or indeed am i talking rubbish regarding the Velop?