Your doing it wrong is all I can say..
Your shared printer doesn't show any issues with nat..
"except that there's one network printer and no need to buy another, so it's given a mapped IP that allows it to appear as 192.168.1.2 from the "home" and also as 10.1.1.2 from the office."
Why do you need/want to nat between these networks?? Please give one actual logical reason why you would nat between these 2 networks.. I have multiple network segments in a home.. Why would I nat between my segments?? Why in the world would I have to map the printer to 10.1.1.2 When I can just access it via 192.168.1.2 while creating firewall rule..
Please give an example that actually makes sense where you question comes into play.. There are millions and of networks available in rfc1918 space.. For what possible reason would I nat those in the same location.. And if the same space is being used remotely or even lets call it the same building where you happen to use 192.168.1.0/24 and someone else used 192.68.1.0/24.. Why do we need to talk and how are we talking - there would have to be a transit network between us.
So you freaking nat their 192.168.1.0/24 to 192.168.2.0/24 or any other space available in 1918… Or one of you change your network would be the better idea..
Your question is a non issue because you can not give an example when it would ever come into play that would make sense... Your outbound rules manual come before auto, and manual can be adjusted.. Where exactly is there a problem?? This is outbound nat keep in mind, not inbound. Your natting your clients behind your interface to your interface when they go out that interface.