@ianhamelton, more configuration options would be good, but my thinking is that again, all of those things you mentioned are commonplace for any screenreader. There's no one advantage to using NVDA as the base other than the fact that it's free. All the things that make it NVDA like object navigation, the keyboard commands, addons, are all pretty windows specific. And it would technically be a misnomer too, since NVDA means non visual desktop access and the ps4 is definitely not a desktop! hahaha. But I see where you're coming from, and to be honest, I don't really care what they call the screenreader as long as it gets made. lol In short, for me personally, the existing base for covering dynamic text to speech scenarios would be the only reason for using NVDA as a base. the stock ESpeak voices with NVDA are horrible, and since voices are mostly designed for windows, the quality of the voices aren't screenreader dependent. And thanks for clarifying about your position. I would say that it has basically all the configuration you need as it stands right now... volume, speech rate, and an on and off function. The only thing missing is pitch and voice selection options, but until more voices get made for it if at all, that option doesn't really have to be there. haha.
Porting may not be as time consuming as rewriting, which is why they would've been smart to do what you suggested and licensing NVDA. The problem there again comes with having to learn the programming environment for the particular screen reader. Again, it would be like porting voiceover to Windows... it might not be as bad as designing a complete screen reader, but I think the process would be enough of a hastle. But I'm not a programmer, these are just educated guesses based on thinking and research. Porting would be less time for sure, but less costly financially? I'm not so sure about that if they had to pay licensing fees for an existing product, though they could probably negotiate something with NV Access. It doesn't seem practical to me, but I'm not a programmer, so you might know more about this than I would.
Ah, my appologies about lack of understanding in regards to the ADA and CVAA. But remember that while it does that now, it was originally introduced soully for party chat and messaging... which makes me think the CVAA, if it wasn't all of the reason, was definitely a huge chunk of it. Also doesn't explain why other regions aren't supported... the maker of the ps4 is a company based in Japan. If it wasn't for the sake of compliance, Japan at least should be supported too along with the US, which is why I think that compliance was definitely a part, demonstrated by the fact that a ps4 that's not bought in this region doesn't even let you cheat by changing the language option. There has to be something there, and it's definitely not an accident.
Either way, this all boils down to the problem that we just aren't a big enough market for them to do anything more than barebones improvements. the TTs started way back in version 2.5 or version 3 of the firmware if I remember right. going through to two numbered versions now, if they really cared I think they would've made some major improvements especially seeing how far ahead of them Microsoft is with the Xbox1. Having said all this, I love my ps4... and if I was asked to choose consoles again, I would make the same choice.