I'm aware of the idea to roll out the POS protocol by using a hybrid model of POS/POW. What are the challenges of such a change? This hybrid model would make mixed adoption(for legacy users and new alike) easier but what are the trade-offs of this?
To be honest I don't see many trade-offs between this, and say moving directly to PoS. In fact, I think moving directly to PoS would face more risks, and possible consequences. PoS is sound in theory, but there are still no large scale PoS implementations on the order of how PoW is built into ethereum or bitcoin. I think the hybrid model is a much better choice since it allows you to build out PoS over-time, stress testing the algorithms, and implementations while also providing the ability to recover from security flaws much easier than if the whole network were built on PoS instead of a hybrid model.