I was able to finally get it work on one of my subnets, but then everything sort of just fell apart because I have a segregated network aside from my main home network and for the life of me I couldn't get it to work on two different subnets. Then throw in the whole issue of firewall rules, since since the prefix my ISP assigns is dynamic; it changes every time the router reboots. I figured I'd have to write a little service to watch the prefixes and adjust the rules as needed but just seems too like too much grief to deal with.
Left it until now when I found that android does some weird shenanigans with DNS so it's back on my radar but it's not something I'm particularly looking forward to struggling with again.
[0] https://openwrt.org/docs/guide-user/firewall/fw3_configurati...