I like this extension.

It would be great if you can add 2 more built-in commands: go to first/last page in current tab history. Currently, I can make it work by making use of user scripts like below:

/* go to first page in history of current tab */ for(let i = 0; i < window.history.length; i++) {window.history.go(-i);}
/* go to last page in history of current tab */ for(let i = 0; i < window.history.length; i++) {window.history.go(i);}

Besides, I noticed some comments saying thie extension doesn't work on firefox's pages (like this one). This is not the limitation of this extension. It is the restriction introduced by Firefox on ALL extensions. And it can be bypassed by about:config:

extensions.webextensions.restrictedDomains (empty it, create this string first if it's not there)
privacy.resistFingerprinting.block_mozAddonManager (set it to true, create this boolean first if it's not there)