Not necessarily doubting here, I'm just surprised that this info never made it into either repository of info for units. I don't suppose there's any source of a dev confirming this?

I'm inclined to take Drip's word on his testing, but I'd like to play with it myself when I get some time to run trials on this.

The part that amazes me most of all is, if true that Cymbi's ability acts as a secondary multiplier then that is an insane ability for a 6* to have, let alone a 5*, and Cymbidium should be the first non-event 5* people should aim for (waifu considerations aside).