WOW, so I am managing work projects VERY SIMILARLY to your approach!
I adapted mine from a GitHub project, was it yours?
In my daily work I manage my team and we work with multiple other teams and individuals internally and externally and have to bounce between them quite a bit, so I almost have to keep a pseudo-CRM in the process along with project & action tracking.
In my approach:
- core tags:
#project/project-name #meeting #sigact (explained below) #action #person and #team
- your
#task becomes #action in my system to avoid confusion with the term task as a checkbox item and to match “action item” terminology
- everything revolves around the day with the calendar & daily notes & templater plugins
- each note averages about 4 templated dataviews (plugin author is working on allowing us to dynamically include queries so we can further standardize and reduce template-built queries)
- daily notes, meetings, and “significant actions” are all in a single
Timeline folder
- everything in timeline folder is prefixed with the day in a standard format:
- daily note:
21.04.Apr.23.Fri
- meeting:
21.04.Apr.23.Fri (M) Some title here
- sigact:
21.04.Apr.23.Fri (S) Some thing I want to specifically note
- ex: copy in text of important email I sent/received, note on decision that was made, etc
-
#action has a from: metadata field that is populated with a link e.g. from: [[Team - Foo]] or from: [[21.04.Apr.23.Fri Some meeting I had]]
- meeting notes, team notes, person notes etc have dataviews showing actions related to them via the
from field
- actions and projects have optional due dates and defer dates, and daily notes run dataview queries almost exactly as you do to show overdue, upcoming due, etc.
I also have Keyboard Maestro shortcuts e.g. Cmd M prompts for a meeting title then it fully automates Obsidian to create a new meeting in the timeline with the appropriate date prefix and template applied and open on my screen ready to enter notes.
There’s more but its crazy effective. It may not be as polished and slick and effective as a dedicated piece of software but it is 80%+ effective AND MASSIVELY CUSTOMIZABLE.
It’s not for ultra-fine-grained task management (i.e. not for grocery lists, chore lists, etc) but it merges my strategy notes with my operational planning and tactical execution notes all in a “single pane of glass” app.
What I DON’T have currently are:
- buttons for new project/action/etc
- next action designations
I was planning to experiment with adding these but you’ve already done that so I’m totally stealing those. 
Thanks for starting this thread!