I give Abubis a special pass, because they sell a business oriented version without the character. The true cost of using FOSS is you don't have any say in what the developer does.
This just confirms OP’s point that "you don't have any say in what the developer does", since the only way to get your modifications in if the developer disagrees is to maintain your own version of the code.
I forget how the phrase goes, but it's something like, "Someone else can do it better than you, but no one will ever care more about what you need than yourself." The point basically being that there are tradeoffs: you are either okay with imperfection, or you have to do it yourself. It appears true, whether it be for software development or home repair.
Sure, and then at some point you get conflicts because whatever thing you modified is not supported anymore and/or the syntax changed for some reason and/or other random issue, and then good luck. Forking works well only if upstream is already stable or you’re fine running an old version.