On this page you will be able to observe how one could utilize gif-engine-js efficiently to display GIF images on a canvas by looking at the source of the page and the script setting things up (main.js).
Please do note that this example here uses Workers to avoid any and all JANK in the UI thread for a pleasant experience. The additional code that was inserted into gif-engine-js.js after the main function declaration can be found in this Gist.
I decided to not include it in the project, because it would make the engine not so bare-bones anymore and if the user wishes to implement a worker addition on their own, then they are more than welcome to transform the engine's code for their own needs or just copy paste my own implementation.