feature request: mini thumbnails in the tabbar

[Ulf3000]

Description

hi this is my own vertical tabs addon which is a userscript though. im hestitant to update it anymore since its always a huge amount of work and can easily break when firefox updates. https://github.com/Ulf3000/vertical-tabcenter

But theres one feature which i would miss extremely when switching to sidebery - > tab thumbnails which help you find the right tabs by just looking quickly at the tabbar .

heres a screenshot , so you can see that its really helpful.

One of the key features was that it would save and load these thumbnails when a sessionstore(snapshot) is saved/restored.
So when you load an older session you would already see all these thumbnails in your tabbar before clicking on the tabs. you can already guess the content and re-evaluating tabs can be minimized alot.

i hope you could make it happen, your addon is really efficient and a workflow enhancement but thats the one feature i need to be able to switch.

theres no performance penalty as far as i can tell, neither in taking the screenshot and downresing nor in loading and displaying the small thumbnails on 100s of tabs.

Thanx for listeneing :)