Hey there,
I installed your extension yesterday, and today I was restarting my laptop and realizing, that the RAM usage hasn't really decreased at all. So, I looked through my open windows and saw, that only the first windows was suspended, all the others were "normal". Then, I clicked on "Suspend all" which made the extension only suspend the active tab in all the windows suspend. And funnily: the RAM usage increased. In order to try a bit more, I used the "Suspend this window" button, which did not really anything. Maybe one additional tab was suspended, espescially if it was the active one. And after testing that in several windows with several tabs, my RAM usage has increased by 700 mb (starting at 1.9 GB to 2.6 GB). There are 8 Windows with 166 tabs open. The first window was opened regularly by clicking on Chrome icon in the taskbar, and all the other windows were opened by the Session Buddy extension. All newly opened tabs should be discarded, suspended and normal tab should also be discarded. (Maybe I'm getting the idea of "discarded" wrong, but I thought this might "suspend" them.)
Running Windows 10 Pro, Chrome 72.0.3626.121 (which is actually updating to the newest version right now).
Regards
Julian