I see there has been a lot of discussions around porting to Ren'Py etc., so I thought I'd add my perspective.
In order to try to fix the "bacon freeze" and the broken load/save functionality on Linux, I've disassembled the whole game. That is, I've extracted the assets, decompiled the code to C#, decrypted all the encrypted strings (which also reveals the password for the vngine files) and removed the additional bogus decoy code.
A lot of the game is actually stored in the translation files, so just for the shit of it, I spent an evening writing a converter to Ren'Py - an incomplete one, I admit, I skipped sounds for instance, but it works and wasn't difficult at all.
So what does it actually take to convert the game to Ren'Py?
1. Dialogue files needs to be converted to rpy scripts - this involves handling audio, video, transitions etc.
2. Stuff such as the main menu and all the interactive parts of the various room and map etc. needs to be written manually as it is currently made as Unity scenes with scripts attached. This part will probably be technically easier for Motkeyz to do as his version of the scripts will be prettier that the decompiled and obfuscated scripts I am working with.
3. Support for older save games could probably be done with a plugin, but is this really worth it?
So no, it will absolutely not take a year to do, but exactly how much time it will take depends on the skill set and time available. Motkeyz is clearly incredible skilled in graphics, there can be no doubt of that, but programming is probably not his strongest skill. I have close to 30 years of programming experience and could probably port the whole game in a few days if I did nothing else - I do however have a job and a family and can probably not dedicate more than a few hours a day to this project.
But here's the catch. I could port the game to Ren'Py for Motkeyz - which I would do for free as I can't have any money involved with erotic games - but it will only make sense if he then actually completes the game with the Ren'Py port. Also, last I checked, piracy and breaking encryption is illegal in the EU where I live, so his concent is crucial. Also, there would be no actual guarantees that I would succeed.
The situation Motkeyz is in seems to be relatively common across these kind of Patreon-based games, and frankly, across game developers in general. So many people want to create a game, but lack the stamina and peserverance necessary to actually follow through. Don't know about the art department, but at least in the programming scene, I know a lot of people on the autism and/or ADHD spectrums, who initially are super focused on the project but later looses focus and simply cannot figure out how to direct their focus back to the project again. I wouldn't be surprised if this is where the VNGINE developer is.
At my work, what I would do is have a friendly talk with the developer about why the task will be given to somebody else for the sake of the project and we would usually find a more suitable task for the developer which he finds exciting (happy developers are productive developers). Usually, the person feels a bit defeated initially, but it is also a burden removed from their shoulders. It is not that they didn't want to complete the task, they simply just couldn't control their focus sufficiently, and that fustrates them. But at my work, I am very focused at removing personal attachment to code and projects, as this is important to make room for constructive criticism in code reviews etc., and to make an example out of myself, I make a bit deal out of pointing out when I have failed or advocating for scrapping stuff I have introduced in the past. Having this kind of environment makes the aforementioned actions easier.
So what should Motkeyz do? I don't know. I don't know the personality of Motkeyz or his partner, so I can't tell what would work and what wouldn't. If Motkeyz agrees to let me make the Ren'Py version, what incentive does the partner then have to finish? - Which then ultimately make it all dependent on a random dude who just happens to have reverse engineered the game. If I don't follow through, Motkeyz will have to do the Ren'Py version himself, so that is also a risk.