After the update to version 5.3.0, the Enpass extension has been sluggish. Sometimes its scripts even become unresponsive on my computer, and I need to force them to stop, disable the extension and re-enable it again:
An example of a page that causes this: https://www.reddit.com/r/olympics/comments/4x89g8/nbc_criticised_for_worst_ever_olympic_coverage_in/ (click on the [-] buttons to collapse comments).
Enpass and Enpass extension 5.3.0
Firefox 48
Ubuntu 16.04/KDE Neon 5.7.