Pretty sure Sublime has "remember last files open" on by default, so I guess Sublime already annoys you?
For the most part the original feature suggestion was something different. I'm not sure if you're familiar with the concept of virtual windows, or virtual desktops, but that is more akin to the idea. You can have multiple desktop "views" with each having separate sets of windows and applications open. You can then swap between the different virtual desktops with keybinds as well as move opened windows and applications to other virtual desktops with keybinds as well.
The base of my idea was to implement THAT into Sublime it's self. So instead of having virtual desktops with windows and applications open, you'd have virtual sessions per se, where each would have it's own tabs and window settings (such as having a window split etc.). That way you could have different parts of your project open at the same time. You can then interact with which part you need to when you want, without having a large number of files open or having to constantly close and open large sets of files.