I'm working on a project related to this and it would help a lot to hear about your experiences through the survey or the comment section here.
Here's a survey link if you have a few minutes: https://forms.gle/syL1XrLAauxd57hr7
I'll often Slack someone who sits right by me instead of just calling their name, because the Slack message is a lot easier to ignore if they are busy. It's virtually always something that doesn't require an immediate, synchronous response, so I don't mind waiting.
(also, clickable survey link - https://forms.gle/syL1XrLAauxd57hr7 )
I learned how to cope with this many years ago. I developed a habit (meaning I don't even really notice that I do this anymore, so it doesn't break my concentration) that if someone is trying to interrupt me while I'm "in the flow", I'll just raise my hand up to them, a bit like "talk to the hand". They know this means go away and come back later, or send me an email.
In any other circumstance, I am very responsive to people.
What I often feel is missing from the equation is the alternative cost: What value is lost from having a culture where it's not socially okay to interrupt a colleague?
I think any model that doesn't take this into consideration is mostly pointless.
The goal should be to identify the optimal number of interruptions. Obviously that's super hard to define, since it's all so dependent on so much state/knowledge etc in people's minds.