I have an existing excel spreadsheet for tracking the progress of activities in a project (simplified version below):

The table is a data source for a power bi dashboard.
I have been asked if this table can be adjusted via the Planner app.
I have copied the tasks to a new plan in Planner, and exported the plan to excel, so I can copy the task IDs to my existing table, so:

I can set a task's Status to complete with a pre-built flow:

But the triggers available are very limited and there isn't a trigger for when a task starts/becomes "In progress".
Is there a way to create a custom trigger "When a task starts...", so I can change the status from "Not Started", to "In progress"?
Then a more advanced version would be "When a task is completed, set next task to in progress".
Any help would be greatly appreciated.
Thanks
Stuart