It seems from this survey RW Cep is dimming by ~ the same amount in Ic and V
http://kws.cetus-net.org/~maehara/VSdata.py
which is significantly different to the Betelgeuse event.
(Thanks to “VY Canis Majoris” on Cloudy Nights for the heads up on this)
https://www.cloudynights.com/topic/854288-rw-cephei-great-dimming/?p=12378723
Cheers
Robin