Suggested this recently, think its a good idea, especially for large decision deposits on contentious matters, which are ultimately the most important to push forward.
Could even be proposed as a treasury spend (common good DDs).
Fear has been referendum killer being called to slash DD though I think this fear is overblown - e.g. Kusama issue #1: Treasury burn, Kappa Sigma Mu and the richest collective you've never heard of - #24 by rich