I use the Client Review Reminder section all of the time.

I download a report in excel that has last review date, next review date and I work off that report to send portfolio review emails from RT. It works fine, but I really want to get away from excel spreadsheets.
Can't rely on the Portfolio Alerts since they are inaccurate as it pertains to reviews that are overdue. i.e. client receives review ever 6 months, last review 3/1/21, next review was to be 9/1/21, it didn't happen so the next review date automatically changes to 3/1/22. There really should be an overdue section that I would f/u on continually. The rollover over of the date is also problematic when you are on a client record and look at the portfolio review date, it would show 3/1/22 and you would think nothing of it unless you client on the Portfolio Review and see that the last review was 3/1/21 which means the 6 mo review is actually overdue. Nothing in the RT systems shows you that it is over due. I would be glad to review how I am making the system work for me, if an effort to help you improve RT.