I feel like every person who plays VNs has probably been where you are at some point. Waiting is frustrating. We all want to see where the story goes while we're still alive enough to enjoy it. That said, though, I think A Perfect Marriage is doing better than many of its peers. The monthly updates, even if short, come out reliably. I look forward every month to playing the new version and talking about the latest developments with you guys. There's a game called Offcuts whose fans have literally been waiting for YEARS to play the promised next update. There's serious talk on the Summer's Gone thread about the game not being finished for decades at the current development pace. Even a game like A Promise Best Left Unkept which updates regularly and has a story that is almost finished is still a long way from actually being done because of all the planned endings. Even if it takes 2-3 years to finish A Perfect Marriage, I think that'd be a pretty reasonable timeline. Rendering images in particular is a slow process that will always be a bottleneck on development barring some sudden technological advance.
Whether you should continue to support the game and developer on Patreon is a deeply personal decision. That's your money going out every month so you should decide what makes the most sense for you and your budget. There's also no rule that says you can't take a break and come back later. Or just pay what you want on Itch after downloading the free update from there.
I kind of agree and kind of disagree. I've actually been involved with the VN community for a pretty long time at this point and am have become selective *because* of my experience, not a lack of it. I've contributed to too many promising games centered around a slow burn philosophy with a dev working on it part time where the game has ended up with an abandoned tag or consistent no-content updated to "expand the (milk patrons) story" or, like you mentioned, colossal periods between updates.
I personally do not think that these games should be viewed from the perspective of how long it took for the game to finish. Ultimately, this is all porn, just in a game medium. I'd even argue that almost all games on this site work off the idea that they are providing independent content for stimulation every time they update. After your game has developed the groundwork it needs for the game to flow correctly and for the story to start to make sense, what needs to be asked for every, or at least most, updates is "Has masturbatory content been provided." I assume the case will be made that the groundwork won't be laid out until v3. If that's the case, sure, but I personally can't justify contributing to a game for a *year* with the expectation that there will be no content for that entire backing period. We don't even know how the sexual CGs are going to look, as we're 4 updates in and haven't seen any. The graphical prowess of a dev to make a sexual scene both realistic looking and arousing is often the make or break for games, so to have that pushed so far in the future makes it hard to guarantee this will be worth it in the end.
The reason games like A Promise Best Left Unkept, the Aederin Studio games, Rick and Morty: A Way Home, etc work is because every update they're moving forward, and they didn't take a year to get to their content. Aederin Studios, last I heard, is a 2 or 3 person team and have released monthly updates for like 2 years, with each update being a worthwhile independent justification for the contribution amount.
Ultimately, I think the most recent update was a step backwards, not forward, and I worry that this is how the next half dozen updates are going to look. Think about it like this: What could the dev possibly add in the first 3 updates of Anna's perspective to make it more worthwhile than those 3 months being used to push the story forward. I think the design philosophy of releasing 5 versions from one perspective and then 5 updates from Anna's perspective is going to kill all of the momentum this game builds. I've seen this script play out too many time, and it almost always leads to burnout and then an abandoned tag. I'd love to be proven wrong, though, as this game has potential. I just can't be asked to fund another game that has potential but no content