An additional comment: my decision to not use PWM was done years ago, and I can not really remember the research I did at that time.
Anyway, trying to clarify some points a little bit more, I discovered that the RGB-Led I cited in the first reply of your question, the WS2812 LED, seems to have only a PWM-frequency of 400 Hz, not the 800KHz I mentioned above - that is the frequncy these units can communicate with. Now 400 Hz is way to low not to show up as intensity stripes during short exposure times.
The troubles you can come into with PWM’ed LEDs is well-known, see for example this video Oh Come All Ye Faithful LED Fix Comparison where a recording suffering from PWM is fixed. Also, this short article here LED Color Shift Under PWM Dimming discusses other issues related to PWM’ed LED setups.
Things like this pushed me into my decision to use constant current sources for driving the LEDs, just to be on the save side.