Workflow for IR-GR

Hi All.

I have two below scenarios by the business can any on please give the suggestion

Scenario1
Workflow to approve a parked invoice - going to 2-way match.

What will be the Adv and Dis adv

Scenario2

Workflow that is triggered when IR is posted without GR. Ability to approve via email. The approval then does the GR.

what are the Adv and Dis Adv

Thanks