Switching vendor is usually no option, we are bound to that vendor because of custom made toolings.
So what we do is remove confirmed date and adjust requested date to a new "best guess" together with the vendor.
However we want to see this visual in the Net Requirments screen because this screen is the go to screen for both sales as supply chain.
We already have a customization making the purchase order line red when it's not confirmed.

If there is no standard functionality we need to expand this funciton.