think this has already been requested for another effect type.
As far as i can make out, flanger rate/speed is set based on a division of the current tempo.
I can understand the need and applications for this but conversely i can see the need for a fixed rate not relative to the tempo.
Scenario- flanger used as a Chorus- type effect in a rig that is used for a fast and a slow song where the delay fx varies with a tap tempo.
id like to be able to have a set flanger rate, just as we do for the chorus effect.