That is correct, but you can add another 19. But I believe you can create another service account, then add 19 more and repeat. It supposed to be fixed soon, but its up to MSFT I believe in Office365 to open it up.
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...