custom-ntp flag

[hyperion4]

Description

custom-ntp doesn't allow ntp to be changed with an extension

Who's implementing?

• I'm willing to implement this feature myself

The problem

I would like to use --custom-ntp=chrome://new-tab-page/ for having that new tab page as default.
But the flag cripples functionality.
For example if a user installs the web store and installs a new tab extension like Humble New Tab extension, then the extension can't change the new tab page.
The user is stuck with the new tab page set by the setting.
If the setting could only change the default, but could also "respect" the change of it from an extension, that would be the ideal solution.

Possible solutions

Maybe a new flag like default-ntp that changes only the default ntp and still allows user to change it with an extension.

Alternatives

No response

Additional context

No response