Take a break, Blumhouse. Then team with Netflix and make a better sequel
This would be my proposal for how to salvage this franchise (and this is obviously just-for-fun, I know nobody is going to actually take this seriously)...
Blumhouse needs to take a break for a few years. Give it 2-3 years. Don't rush it. Because we saw what happens when they rush things.
We got three very solid, fun horror films that told a singular, coherent story that felt more-or-less complete. Then a contrived fourth film that raised more questions than answers about the franchise. It should have just been a spin-off or the start of a new storyline. Then we did get a spin-off, and it was a slight step forward because it wasn't too bogged-down by the then-messy central storyline. ... ... ...then they gave us another rushed main-series sequel that just created more questions and felt like a tonal betrayal. It also included all sorts of bizarre ret-cons and alterations to the central storyling to boot! And it was a let-down.
They should take a break... hold occasional meetings, or take pitches from the original core creative team (Oren Peli, Christopher Landon, maybe even Joost & Schulman) and develop them, but not rush it.
Then, find a streaming platform like Netflix or Hulu. Someone they can team with. And make another entry that is either a spin-off or another follow-up that doesn't pay much attention to the mess that was The Ghost Dimension. The films almost exclusively functioned better for at-home viewings in the dark than they did in theaters, so a streaming service would be a great way to go- it wouldn't entail the risks of a theatrical exhibition, and it would make the film readily-available for fans when they wanted it.
Maybe launch it the day before Halloween, before giving it a proper DVD/Blu-Ray release the following January, as has been tradition.
This is what they should do. They won't. But they should.
And FURTHERMORE, this is my signature! SERIOUSLY! Did you think I was still talking about my point?