If you point the PiHole Upstream DNS to your router's DNS (Or whatever DNS server is hosting the .local domains) it should resolve .local hostnames again. I think by default it uses 8.8.8.8 or 8.8.4.4
Thanks! I've tried that, but then got switched around with what was pointing where. DNS is definitely a part of the stack that still confuses me, despite on the surface seeming somewhat simple!