But you can already do that with reaction speed technically, and of course with future sight.
Even in a situation for someone with 120 reaction speed or higher, the person can't always react to everything which still allows more subtle use of CoO. I never use it but I see several scenarios with adding attack speed can be problematic even in a RP setting depending on how the difference in CoO is done for calculation.
Scenario 1: Difference is only added when both people are using it (Which makes the most sense in the current system), Person A use it attack faster which in turn forces Person B to use it or get blitz'd.
Scenario 2: Difference done regardless of activation (which makes no sense since then there's not much point in using it in the first place). Everyone still must have 100 CoO in the 'end game' purely for the purpose of not getting suddenly blitz by someone, especially since 1 stat difference can be a difference of brackets.
This also means that someone with 120 CoO precognition and 120 MA(or the equivalents) will always outspeed anyone that does not have the 120 CoO in terms of attack speed.
The difference from WURP and this is that it is harder to justify using CoO because it is purposely nerfed to be a turn base prediction system and that it requires you to have 100 in it to use it in combat. This system(the one in the skills & abilities thread) simply allows you to have better reaction so people can't straight up blitz you, which means that non-Zoan users have some ways to deal Zoan users especially for non-DF users.
Take me using CoO against Guren in Wano for example. If I had use attack speed increase, I could potentially blitz him since he wouldn't be able to react without using CoO in return. You can argue that 'oh then there's just bad RP to use it like this', but it doesn't change from how the system could work.