Thank you Jean Marie, helpful !

However, without the time to dive in to the sub comps, is it possible there is something with the "size + position" subcomp, where if used after a "position only" sub com it works, but if used first without the "position only" subcomp beforehand (connecting a cable to a "position only" subcomp, launch, re-connect the cable to the "position + size" subcomp, relaunch), it sets a window size of 0x0, aka you get no window ?

Also, from a non-coder perspective I don't know if there is a better way to achieve this but, are these subcompositions the end version of how Vuo will remember window size and position for exported apps ? (I guess for Vuo compositions The composition view should have the previous size and pos after pressing Stop->Run in the Editor will be used, but as micpool wrote there, will that option also work for exported apps ?)