From Pixinsight :

We are glad to announce the release of a new version of our CometAlignment module: 1.3.5 for Linux, macOS and Windows. This version is now available as an update to the current PixInsight 1.8.9-1 version.The CometAlignment tool has been designed to align fast–moving objects, such as asteroids and comets, interactively among the stars. The process also allows you to perform subtraction operations among frames to obtain images of the star field without the comet or a starless comet.     The new version we have released today is a complete redesign and reimplementation with significant improvements and new features. See the official announcement on PixInsight Forum for complete information. See also the reference documentation we have just published on our corporate website.     We hope you enjoy this release. Thank you for your attention,     The PixInsight Team at Pleiades Astrophoto