Are you wanting the entire navigation unit assembly, or just the touchscreen? If the latter, I should have one from an otherwise bricked head unit. Feel free to DM.
I was going to say, but Matt beat me to it, that the bare touchscreen might be interchangeable with the ICE RAV4 of similar vintage, such as 86100-0R032 (note: one digit difference from the EV version 86100-0R033).
This would have to be researched or pioneered, but if I was in your situation, and couldn't find a reasonably priced used nav unit, I'd be tearing into mine to see if an ICE version's bare display could be made to work.
I am by no means an expert on ICE models, but I don't think there was ever an ICE RAV4 that used the home button interface like the EV. I think the 032 version is just an older rev of the same functional assembly.
The only notable benefit of the factory nav unit is the ability to toggle on/off the extended charge function. At this point, nearly all RAV4 EV battery packs have lost enough capacity that there is little if any range improvement from extended charge. Other forum members have successfully upgraded to more modern head units equipped with Car Play/Android Auto, and may be a route you consider.
Well, yeah, some can -- a whole lot of the lower-end EVSEs don't have scheduling, esp. "fat snake" mobile ones. What I was implying is that I think more is lost, in replacing the OEM nav unit with aftermarket, than only access to the standard/extended range toggle feature.