I left Firefox for a number of years already. Did Firefox changed its Tab Unloading behaviour? I remember Firefox will unload Tabs that are inactive after a period of time. So having OOM crash on Firefox was a relatively rare occurrence even when I had hundreds if not thousands of tabs.
If you had restore tabs on restart then tabs that were in the background and not pinned would not be loaded until focused. Tabs would not be unloaded unless you restart the browser. The first implementations were in the Fx 20 range and some additional improvements in the 55 timeframe. The feature in 93 is suspending without the need to restart the browser.
I've never seen Firefox unload an inactive tab without my permission, but it looks like according to the docs it's had a 'memory is low, unload tabs' mechanism since 2019. It looks like that behavior was further adjusted in this release, though it's not clear to me what the difference is.
>though it's not clear to me what the difference is
This one works well enough that we can default it on :-)
The previous one didn't reliably detect low memory situations and you could crash with OOM before it ever triggered. The article goes into detail about the various signals that have to be monitored on Windows. We had to do some work on gathering the metrics and correlating with crash data to determine when to trigger.
