Instead of PoW change could it be possible to add a supplementary PoS layer which requires a block to be validated in some way by nodes prior to miners being able to build the next block, reducing the centralizing effect of propagation times?
A hybrid PoW / PoS version should be investigated as well, my only concern is that we should keep the PoW HF as simple as possible and adding a "secure PoS" algo into the mix will be sure to complicate the HF as no
secure PoS really exist and politically adding PoS to bitcoin will be much more difficult.
I'm glad you think its worth looking at, thanks.
The benefit I think is that miners will fight a PoW change tooth and nail and may gain some sympathy for that from users, because it is a little bit unfair to miners even if it does have benefits and will look to many like a major change. If miners fight such a supplementary PoS they are transparently only doing so in the self-interest of big pools trying to centralize power. So perhaps it won't be more difficult politically.
Also perhaps security is less of an issue for PoS if it could be structured as a supplementary layer which doesn't actually secure transactions, only serves to reduce centralization?