This part won’t happen because of processing load considerations and performance issues for real-time payout of ratting and mission rewards; it’s why we have 20 minute payouts in the first place.
I can see how it would be nice to have a running counter of ‘here is what is due in my next tick’, but I suspect doing so would have the same issue as actually paying the activities out at the time of earning. If CCP could tell your wallet what is pending without performance issues, I’m pretty sure they could also deliver the ISK without said issues. Since they cannot deliver the ISK immediately, it is highly suggestive that they cannot deliver the data that is paired with the ISK immediately, either.
Check out the services and third party development subforums - someone may have written a tool to analyze your log files and estimate this data for you. It’s worth looking if you think you need it.