@DanielJLewis,
Unless there’s a particularly significant issue with Shields, the effectiveness of the “jittering” technique you described is likely just a coincidence. Is there a set of steps and sites in which I can test myself to confirm that this behavior (“jittering”) occurs as you report it?
@Sam1 @pacificananda,
On my end, I was able to simply install the Boomerang Gmail extension and start using it immediately:
For anyone having issues with the extension, would you mind trying to clear your gmail cache/site data, relaunch the browser then try installing the Boomerang extension again (note that you’ll have to re-authenticate into gmail)?