Ive been around the block a few times to see a blackmail route open when I see it. Its pretty obvious that the uncle scene is going to open up some options with the sister, aunt, and uncle. Just be careful how you approach NTR as it really pisses some people off when its forced.
Not really.
Those of us that really hate NTR only need to know if it's in the game or not. If it is we know to avoid it.
The only time we get annoyed is if we play a game that doesn't have NTR and the dev makes it clear there is not NTR and then adds it in half way through. It means we got attached to characters and a game, either emotionally or financially through patreon, and we have to stop playing.
If I know NTR is in from the start i'm left with 2 choices, play or don't. If it's a small insignificant part that needs to be played a certain way to see I don't tend to mind but if it's a big part of the game or, like I found out for this one from this forum, it's unavoidable then I won't play it.
Those that get pissed off are usually just looking to bitch about something. It's been well documented how much I dislike any and all forms of NTR but the only time i've voiced a complaint is when it was added to a game that a dev previously said wouldn't contain it.
The big problem is while NTR fans can play games that don't contain NTR, those of us that don't like NTR can't play games that have it. The easiest way around it is to avoid any games that have it unless, as I said, it's a minute easily avoidable part that has a flashing neon sign saying "NTR THIS WAY". If it is a big part or unavoidable then I avoid the game, problem solved.