Probably the best way to tackle this is to edit your profile preferences and change it from "all one page" to a smaller amount of comments.

I think the jpegs and gif's some people upload are the real killer, as youtube is taking most of the hit on youtube embeds.

Or I'm sure it wont be hard to add a menu to your prefs to give what you want.

I don't know what it's like now but Firefox, and certainly Firefox running adblock used to freeze up really badly with a lot of embeds, it was the final straw that pushed me to chrome as my default.

Im sure learning how to write web plugins could easily do this

Just run noscript and block youtube.com until you actually need to use it. Change noscript's settings so that it only refreshes the current tab when you allow a page to run scripts.

What I do is "temporarily allow" youtube, and then I can always revoke temporary permissions when I don't want youtube shit everywhere.

Noscript should be pretty much mandatory anyway for general internet security.

FYI, I now found a way to do this, with the following userscript: https://openuserjs.org/scripts/ConnorBehan/St..._Embedding
Use Violentmonkey to install. If you add the following line in the top bit, you can restrict it to ESR only:
// @include *esreality.com/*

Replaces all embeds with plain links.