"RO5 isn't yet optimised for...". Rather meaningless, sadly. Since "optimised" means the best code ever for the system, that's rarely going to be the case except in very small cases, and hard to prove. So you could say the same thing about any OS/hardware combination, and that's also why compiler engineers prefer the term "code improvement". So, you could certainly improve the code in both RO5 and Adjust for the processors it runs on, but the question is of effort and the kinds of performance improvement you would see from that effort - often a case of diminishing returns.