I hope this short comment will motivate you to supervise the addition of what you wrote about the OBI protocol to the whitepaper

I'm actually not one of the main maintainers of the whitepaper, although I've suggested ideas for it and helped proofread it. But I'll definitely answer any questions that may come up about this when it gets updated (I guess it would probably be a good idea to do it soon, with the upcoming hardfork).

ps: If you have a link explaining as well how the scheduled block producers work in detail I would be interested as I'm having a hard time understanding its exact process.

I don't have such a link unfortunately: we had to read thru the existing code to figure out how it worked and how to update it. We try to add comments as we make changes to the code, but for the most part the original code didn't come with many comments.

ps: why can't we use the same options for the reward on comments as on posts (e.g.: decline the reward), what logic led to this differentiation?

AFAIK, you can decline the rewards for a comment (not just for posts). I think it's just a matter of if the frontends expose the functionality. But I could be wrong, and it's probably best to ask in frontend devs discord for more/better info on how to do it.