Tacere 2.1.0 beta 4 pushed to the Play Store.
This release adds support for changing the ringer for all instances of a repeating event in one go. Apk is available from the GitHub repository.
If you have subscribed for beta releases through the Play Store then the update should begin automatically within a few hours. If you wish to test to the beta releases instructions on how to subscribe are available on the Tacere Beta community.