I was at Yahoo when they did a big email redesign, and the new design didn't work for 1/2 their users. Digging deeper, they found that email users kinda fall into 2 camps: filers and pilers. Filers carefully organize their data so they can quickly navigate to their target. Pilers just collect stuff in a big pile and use search to find their target.
Sounds like you're a filer (I am too). Sounds like emdash is kind of a mix of filing and piling.
I don't know about "hero" use cases, but I use actors (state machine responding to events in a queue) quite a bit when making hobby Arduino devices. It allows me to have a "button" device that can work with both the hardware pin interrupt controller and a clock to generate "click" and "hold" events, to pass to other actors in the system. I also will also use an actor to manage an I2C device, so that that actor can detect errors and restart the device to recover from errors. You could do either of those things without actors, but doing so has made it easier for me to compartmentalize my code and organize how data flows and states change.
I think it was their thread/process scheduler. It had a section of priorities which got hard realtime scheduling, then lower priority stuff got more "traditional" scheduling. (Alas, I don't know too much about thread/process scheduling so the details elude me.) That way the playback threads (and also other UI threads such as the window system) got the timeslices they needed.
I'm in the middle of building a 1000sf home with some friends. It'll probably be about 80k for the house (including various permits). We hired contactors for: plans (including engineering calcs), concrete slab finishing (our floor, did the forms & rebar ourselves), trusses (required by code), plumbing, and drywall. I just got back from putting tile in the bathrooms :) We had a retired electrician friend who guided us but did that ourselves, otherwise we probably would have hired one. We're in the countryside so also needed a well and septic system (not part of the 80k).
It's been a tremendous amount of work but is otherwise rather doable. The internet/youtube has been very helpful (like Neo downloading how to kungfu). Another surprise is how helpful the building inspectors have been. They're usually dealing with cranky contractors who want to do the minimum, and we've been very eager for their advice on how to make things last since we'll be living there.
It's been notably more expensive (maybe 15-20%) than we expected, mainly do to the modern building practices and materials which are either required by code or just a good idea.
Sounds like you're a filer (I am too). Sounds like emdash is kind of a mix of filing and piling.