Made the switch this morning, and the Internet still works over both the ethernet and wifi devices, so that's looking good!
The one thing that I can't figure out from this tutorial (How do I use Pi-hole's built in DHCP server (and why would I want to)?) is once I've set up pi-hole as the DHCP server, how to route all DNS requests through it. I'm a bit leery of breaking something, so I'm not trying to experiment too much, but I've tried this:
...to see if I can force all traffic through the static pi-hole IP address (192.168.2.19), but that just gives me this notification:
...and I can't see anywhere on the DHCP page itself to set the DNS address.
EDIT: I've also tried setting the upstream DNS address to be the router's IP:
...with the same results. I'm also surprised not to see any DHCP leases on the Pi-Hole Settings > DHCP page:
...I've reconfirmed that the router DHCP is off, so Pi-Hole's DHCP should be creating leases now, right?