Well, probably not surprising, but I disagree, and I would be opposed to such a change. The original spec for SPS stated that voting for proposals would work like voting for witnesses. And it was not an accident that we didn't create a separate proxy process for proposals. Adding the need to set multiple proxies for two very similar kinds of voting just means more things for a user to manage. In practice, I don't think most users should be proxying their vote anyways. The two main cases where I think it makes sense to proxy your vote is 1) when you have multiple accounts (this applies to a number of large stakeholders) and 2) when you're no longer actively involved in steem and are just holding a passive investment. In both of these cases, you're probably going to want both to proxy to the same place.