Forcing start date & view despite the cookie

What is the best way to ask the scheduler to display a specific start date /view when using cookie extension? Most of the time, doing what the user did last is best, but once in a while we want to display a fundamentally different thing.

I can delete the cookie set by cookie extension via js. Is that the only approach?

Yep, it is the only solution
We will think about adding some flag to simplify such use-case in next versions.