While a Western studio would most likely have the budget to pull off an Umineko movie, Umineko is an Eastern story with Eastern nuances that a lot of Westerners get, like the chain of karma and a lot of the concept of gender roles that are essential to Umineko (I’ve tried to explain things about like with Eva not being the head of the family to my cousins and they didn’t understand at all, no matter how I explained it).
To be honest, while the anime did so much wrong (and it irks me to this day there’s not a whole lot that’s perfect for editing), I did like their way of handling the Red and Blue Truths. But I would like it the way that the fanmade EP4 Tea Party handled it, no fancy color-changing backgrounds, just Red and Blue words on screen, flying and vanishing once the speaker’s done. It would make certain scenes far more effective, like the Red Text Web scene (imagine the words slowly transforming into parts of a web.) That’s how that should be handled.
Since Umineko was so text-heavy, and as far as I’ve heard (I’ve only read on Harry Potter book and didn’t like it, you are free to burn me at the stake for my heresy), the Harry Potter movies left out a lot of stuff and took weird directions, I would say a long TV series like Game of Thrones has would be appropriate. It wouldn’t have a movie’s ginormous budget, but you’d be able to fit the important scenes in while being able to cut down some wordiness (because let’s be honest, Ryukishi is a wordy mofo). I agree with @MrDent’s thing about the magical scenes. The manga has brilliant representations of scenes that are otherwise akin to a slow-moving 100-car freight train of text, and if people are just sitting around in this show, audiences will be bored, and that’s no good, no good at all! Like, Higurashi’s recent TV drama looked cool, could you imagine how cool an Umineko TV drama would look?
I agree, though, an hour long per episode thing would be best, like for example, if we were doing EP3, the first episode could end shortly before Beato narrates her past. Then the second episode for the arc picks up from there, and ends with Eva solving the epitaph. The third episode picks up with Eva discovering the gold, and ends with Rosa and Maria deciding to go outside. The fourth episode picks up with EVA meeting them in the garden, and goes to just before Kyrie and Rudolf’s showdown. The fifth episode picks up with the showdown, and ends with George and Beato leaving. The sixth episode starts with George and Beato trying to bring back Shannon, and then ends with Beato being shot through the heart. The seventh episode is dedicated to most of the Meta fight, and ends with the start of the Red Text Web scene. The eighth episode is that scene and ends with a certain someone stating she’ll expose the truth of Rokkenjima 1986. The final episode is dedicated to the Tea Party and the ??? Tea Party, and it ends with Activepain playing as the credits roll, and at the end, you’ll see a “To be continued in: Episode 4: Alliance of the Golden Witch.”