1. As you yourself point out you need approval from Igiss since you are basically editing his mod and taking features and models from it*, while adding own.
2. Lots of the features are basically add-ons** that could be just as well used in discovery without changing anything. Think it will be beneficial to instead join discovery development***.
True, we are waiting that, but we aren't wasting time in the meanwhile. If Igiss doesn't approves it, we can just throw it as an OpenSP mod. And why wouldn't he want a spin-off? Do you think that everyone will run from Discovery .86 to DAU? Come on, DAU will be nothing compared to .86 if you do it right.
* Not quite, everything is getting replaced except for the vanilla models
** True, but can I really believe that the Discovery Dev Team will add this?
*** I've dedicated a lot of time doing this already, I've asked Frozenballs if he wanted some ALE. editing done by me some while ago, on the thread that he opened. But I didn't got replied back, so I didn't insisted.
EDIT ***: And to see all the community's / our ideas become vain smoke? No thanks actually.