How can we enable or disable any workflow launcher based on feature flag value.
Any suggestion please.
Yes, you can enable/disable launcher based on the feature flag.More info about feature flag at https://aemlab.blogspot.com/2018/06/sling-feature-flag.html
What do you mean with "Feature flag"? Is it the sling feature with the same name  or do you refer to the software development pattern (which is not tied to any implementation)?
In any way, each workflow launcher has a flag "enabled", which you can set (based on any type of code or automation).