I think this is only practical of there is a way to aggregate the stakeholders' positions for quick reference. e.g. Applicants can see that '30% of the HP support I need for my DHF application can be achieved via stakeholders who say they will vote for proposals that meet my own one's configuration'.

Not a bad idea at all. This could be done in a super simple way, by having a dedicated post and people put comments under it - one criterion/consideration per comment. Stakeholders then vote on the criteria they identify with.