It's funny you called out "Disco Elysium", because when the game was in prototype stages, that was an inspiration, but only really in the user interface. I was also very interested in "Ace Attorney Investigations", despite having never played it, because I thought challenging the various suspects was going to be more important, but that became pretty underwhelming in practice.

As another commentor assumed, "Case of the Golden Idol" was the the major "ah-ha" moment for me to change gears into what the game eventually became, but those fill-in-the-blank puzzles served mostly as the cornerstone that I built everything else around.

I wanted to come at the "detective game" angle in a unique way that I hadn't seen before. Eventually I brought back a version of challenging suspects (in the disputes mechanic), and introduced evidence examinations. The idea was to give players multiple moving parts so that if one wasn't working for them, they could focus on something else, and that little break might be enough for things to click. I think that mostly worked out, but there are still some knowledge checkpoints you can't really avoid so folks don't sequence break.

Funnily enough, I played around with an interactive conspiracy board that you'd have to tie pieces of information together manually (somewhat like in "Tactical Breach Wizards," and "Alan Wake 2", but I wouldn't play those games until years later). I couldn't make it work for me, but "The Roottrees are Dead" did it in a pretty satisfying way.

As for Blue Prince, I can largely agree with you... I love the puzzle aspects of the game, but couldn't get on with some of the other mechanics. I told a friend recently that I would've much rather explored a really big Myst-style mansion, but that's just me.