I realize this may be a VST issue and not a ableton issue, but I've seen other DAW's have a window set feature where you can save where you like your plugin windows to appear when you open them
I use multiple monitors I general like my meters plugins on one screen and Synths/effects on another. Whenever I open some plugin windows they appear on top of the main Ableton window and I have to move them, for some they seem to re-open in the same session and remember. When I close Ableton and re-open everything is forgotten and I have to reposition everything. I'd love to see a feature where plugin windows remember their previous positions or a way to "save" the positions with the session so they always open in the same location/display.