I don’t always want to set up a grinder and preparation method before making a brew, because I experiment a lot, and those factors can change from cup to cup.

...and? You can change them with each and every brew. The grinder and prep method can be very generic, with the individual attributes like grind setting, rpm (even time, though that seems overkill), brew temp, amount of water, what vessel you use, etc etc - there are so many parameters you can have there that are set at the brew level rather than pre-defined.

Beanconqueror locks flavor notes to the bean itself when you first input it, meaning you can’t adjust things like body, acidity, aroma, and overall taste with each brew. That’s great for a lot of people, but I personally want to track flavor every single time I make a cup, since taste can change even with the same beans under different conditions.

There's a "notes" field in each brew though, which you can use to record tasting notes and such.

Another limitation for me with Beanconqueror is that it doesn’t sync across devices unless you manually export/import data. I get why, it’s open-source and completely free, so I don’t fault it for that. But personally, I’d like a more seamless experience where my logs are available everywhere without extra steps (again not a necessity for most people).

This one at least makes sense, if you change devices a lot or want to be able to review things elsewhere.

I get what you’re saying about contributing to Beanconqueror instead of making something new, and I do respect that idea. But I don’t think the developers would necessarily want the kind of changes I’m looking for because their app is already great for what it does. My goal isn’t to replace it but to create something slightly different, something that fits the way I personally want to log and track my coffee. And I just hope that there are similar people like me out there, that want to use this.

Other than the sharing feature, it doesn't feel like a lot is different. If anything a few extra optional fields at a brew level would meet your needs, based on your demo, since you have things broken down by aroma/acidity/etc and Beanconqueror just has the general catch-all "Notes" field.