Opportunity is missed by most people because it is dressed in overalls and looks like work. - Thomas Edison
For quite a few years we've used an app called Grexit to share labels across all the email accounts
We suck at it, just fwding emails back and forth and around and at times it because confusing. We have to change it at some point. Interested where this thread goes.
Since this thread we also switched to Streak. Incredible app and we use it for a ton of thing beyond crm, including production workflow and production/order data. But yes, having to click "view unified thread" doesn't exactly feel like email sharing. You can't jump in and reply all on a thread and instead must start a new thread. That said, we spoke with them about this initially and it's more of a gmail or maybe email in general thing. If you aren't originally included/copied you can't reply in on the thread. I'm not sure how Grexit/Hiver did this honestly. All in all the benefits of Streak in other areas make the slightly clunky email sharing worth it for us. It's obvious to me that google wants third parties to get their cut of the market, otherwise they'd have the ability to folder an email thread in Drive or mirror labels to drive folders. That feature alone might wipe out the need for lord knows how many other apps.
Our workflow is pretty basic, no shared email account or group yet, we like to have personal email addresses v. generic ones but that will have to change soon. I like the way you are thinking of doing it a lot. For now, client emails one of our sales reps, any of the three of us who can rep a job claim it, box it, reply to client. When the box is created a folder with the same name is auto generated in Drive under our Quoted folder (api call). Jobs move through the pipeline and, once active, we kick in a lot of columns in Streak to help us with production workflow. Printavo cannot handle non-linear workflow status changes or things that are cumulative but Streak does great at it. It wasn't what the Streak folks intended it to do but if you dial it in right it performs well. Screen shots attached of two of the specific views we have- Ready by Press and Screen to Coat. (our POs are descriptive so I scratched them out for privacy's sake) I have a view like this for each department and each step needed to get the job to press. Working on tuning up java coding in some cells for auto calc of press run times and labor hours needed in each dept.