I've worked remotely for a little over 10 years. The approach I like is: start with IM (or sometimes email) and then move to voice if your real-time chat takes longer than a few minutes or a handful of back-and-forth volleys. At some point someone just sends: voice? (which is usually video/screen call). Depending on the problem worked on it means the person in the office (cubicle farm) may need to get up and grab a meeting room to avoid bugging their coworkers with the call. They might respond with a link to the video conference line/room, or with a better time in the future: 2pm?

That way you're not bugging people with a voice call for what turns out to be easily answered questions. But the culture allows for quick transition to voice and you don't get sucked into long IM conversations spinning your wheels due to miscommunication.

Not responding to IM until later with a 'sorry, was heads-down/afk/whatever' needs to be acceptable too, otherwise you get the problems of people expecting everyone's instant response all the time.

That said, I miss the old MSN messenger feature of 'buzzing' someone, which would animate/vibrate their IM window and play a soft buzz sound. I sometimes use the slack call feature for this (just ring and hang up), but that doesn't quite relay what I'm looking for - something less urgent than an immediate voice call, but lets the person know I'm likely blocked waiting for their answer. There's always that game that plays in your head - if I get an answer in < 1 minute, I'll stay on this task; if it takes longer, I'll spin up a different task I'm not blocked on...

I'm a fan of form follows function. So every project is different, and every set of coworkers are different. For the type of work I do, with high autonomy groups, I wouldn't make the same choices as you.

I've found phone calls disrupt my flow, but instant messaging disrupts it a lot more. People are less likely to make a call than to send an IM. As a result, I would get a lot more IM's than calls.

In my last job I had a rule: People who are with me on the site have to come to me physically (or email if not urgent). Remote people can use Skype, but they must call me - not IM. Of course, they can still email if it's not urgent.

People still called, but the volume went down quite a bit.

How is this different from saying “my chair feels good so any manager who makes me get out of my chair is a bad manager”?

Flow feels good, that doesn’t mean it is good, or that interrupting it for collaborative work isn’t overall more beneficial.

Well, some people believe people's opinions matter. And some people believe that intrinsic motivation is important. And some people believe that autonomy is something worth striving for. Of course, there are plenty who disagree, and you should feel free to associate with those who hold your values.

Does Slack not disrupt your flow? Or putting an email together?

Personally I find that they can, but they don't have to. I can put off Slack/email until I hit a stopping point, or I can wedge it into the middle of a long-running process (start a build/test-cycle/deployment, then go answer Slack). At the very least I can finish the chunk of code/whatever I was working on. Phone calls and in-person talking are a hard interrupt, drop all my context on the floor and get nothing else done.

Those feel more comfortable and they count has hours worked, so it doesn't matter that they are far less time-efficient.