What about NTS bleeding onto the NTR path, like in
Man Who Fell for a Knightess Whore Has His Cuckoldry Fetish Deepen? Sorry, not a western game.
To me, cuckoldry has no appeal at all, as it's generally portrayed: a submissive, masochistic desire to see one's love interest taken by a "better bull". Even when the fetish is the LI's sluttiness, the cuckold who only watches and jerks off to others fucking her is something I can't relate to. Take out the MC jerking off and being submissive and put some power dynamic in, such as the LI asserting control over the situation (or better yet, the couple doing so, complicitly), avoid the BBC trope altogether, and it may work - but then it's not exactly cuckoldry. The problem is we don't have enough "tags" for all the variations and the ones people use (like NTS) are too broad, including scenarios that are diametrically opposed in terms of tone, character portrayal and dynamics.
The devil's in the details, and to answer your question directly, an NTR path that could bleed on NTS could world for me, depending on so many factors that, most of the times, it doesn't. An example of where it did work would be
The Spellbook - a game I hated the beginning of and only kept playing beyond the part where the "best friend" (trope) takes advantage of the MC sharing certain knowledge with him to try and steal his gf, because of spoilers. Not a particularly well written one, but it does give you the satisfaction letting the MC "man up", take back control of the situation and stop his "best friend" before he took her away, but not before they did things together - how much, it's up to your choices. MC and gf talk, both take responsibility - not entirely in the case of the MC, but that's down to the game's main theme of mind control - and to try an open relationship, and the rest of the path has more interesting shenanigans. It's not my favourite by a long mile, but it works, because the MC comes out on top. But if an NTR path becomes NTS because the MC is a wimp and accepts the situation, nothing changes from the NTR, imho. To many people, "consensual" makes the whole difference, but if the dynamic is still that of a passive, surrendered, emasculated MC, it's still NTR to me, if not by definition, at least in tone.