A critical feature for me is a more intuitive management feature. Current implementation is similar to functionality seen in Vivaldi (which is an improvement over most other browsers), but it would be worth looking at the Tabs Outliner extension for Chrome to see how a more robust system could be implemented.
Tabs Outliner is one of the most useful and highest-rated extensions in the Chrome Web Store for tab management, even though the extension is prone to frequent crashing and is no longer maintained since Jan 2016. There is an active community for the extension here where the Ukrainian developer occasionally responds to user feedback, but doesn’t have the motivation to move the project forward.
When used in conjunction with the Great Suspender, the ability to manage session memory and tab grouping makes browsing the internet much more intuitive and removes the need to constantly be manually cleaning tab history to avoid clutter and system slow downs.
At the very least, I would be satisfied with the ability to sort history by when a tab was closed, rather than opened. This would be closer to Noguchi filing system methods where the “last touched” information carries more weight. I don’t understand why all browsers lack the ability to sort by “time closed” or maybe even “total time left opened”.