This add-on is probably the best one for this feature.

I will put here some suggesions and/or wishes for improving/enhancing it [:-D]:
- Please... PLEASE... add/make keyboard shortcut(s) possible, PLEASE.
- Move the button to be on top when the pinned button in the taskbar is pressed.
- Possibility for suspend multiple tabs at the same time.
- Add option to disable the creation of screenshots.
- Add other options to toggle, for example, not discard tabs that are playing audio or have some form with information in it, and/or others.
- Make possible to disable the auto discard tabs after some time (it's possible to put an abnormal value manually but it's not the same).
- Make possible to choose more than 60 minutes using the arrow keys in the GUI (I know that manually it accepts bigger values).
- Maybe, add tab context menu support.
- Maybe, look at options in other similar add-ons like the 'Auto Tab Discard', for example, for more ideas. ;-)

Anyway even if you ignore all of these very very thanks for this add-on. :-)

why you need access to all sites data?

this is the best extension of all it kind. simple, and full function

The feature of capturing a screenshot of the tab before suspending is unique and very helpful, it's the reason that I use this extension instead of other tab suspension extensions!
Features that I'd love to see are context menu and a disable option with a blacklist for domains that I want to keep getting suspended.

If you want a tab suspender add on for Firefox, use this one. Every other suspender available for this browser seems to not understand that tabs can play audio and designing your suspender to automatically load a page because it was selected for any reason means this audio will start playing.

This one lets you choose to load a page with a click. Its so simple but its so nice not having to go back through my tabs to find the one that just loaded because I used a hotkey to close a tab I needed for just a moment and started blasting audio.