I know the relative power dynamic can complicate things... but, it sounds like you need to stand up for yourself more. Tell the stakeholder that no more work wi

I know the relative power dynamic can complicate things... but, it sounds like you need to stand up for yourself more. Tell the stakeholder that no more work will be done until a decision is made. You have done your part, the stakeholder has the authority to make the decision so on their head be it. If that doesn't work then you have three options: escalate to their boss, live with it, or quit.