Working from one project, not four spreadsheets
A project reported from separate spreadsheets has separate versions of the truth. Reconciling them is most of what status reporting consists of.
The point is that the numbers cannot disagree
When the schedule lives in one file, the resource plan in another and the report in a third, the three drift apart within a fortnight. Nobody is careless; they just get updated at different moments by different people.
When one task list drives the schedule, the resource loading, the dashboard and the report, changing a duration moves every view together. There is only one project, so there is only one answer.
Local-first is a constraint, not a slogan
A project plan carries client names, budgets, staff assignments and commercial dates. None of that has any business on somebody else's server as the price of doing arithmetic.
Saving to a browser means this browser, on this device. Exporting gives you a JSON file that is yours — the backup, the way to move between machines, and the way to hand it to a colleague. There is no other copy anywhere, which is the point and also the responsibility.
Every indicator should say what produced it
A dashboard status you cannot check is a status you cannot trust. Each figure should name the data behind it and the threshold that turned it a colour, so it can be argued with.
That is what separates a derived indicator from a judgement wearing a traffic light.
What an integrated workspace should refuse to do
No collaboration, no notifications, no assigning work that emails somebody. Those need a server and an account, and the moment they exist the privacy claim stops being true.
If a team needs to work in one place simultaneously, a local-first tool is the wrong choice and should say so rather than half-implementing it.
Breadth and depth are different jobs
An integrated view is for seeing the whole project at once. It will always be shallower than a tool built for one question.
Monte Carlo simulation, schedule crashing, earned value and AHP each go considerably further on their own pages. Use the workspace to see the shape and the standalone tools when a specific question needs a real answer.