While I'm happy to hear there isn't a penalty (I wasn't really expecting one), the behavior was still very much present. I know I switched modes at approximately 10:30 and at 22:30. While I could understand the current block not being switched, the change actually took 6 blocks each way, equal to about 5 hours on average after I changed the settings. This happened on two different occasions. I have two miners running, both were switched at the same time.
Thanks for your report, I'll check this.
If you see less "reward" per some number of shares it doesn't means that your reward was lost, it means that some of those shares were correctly or accidentally accounted as PPS and thus not shown.