cherrybim- i just reviewed Rav heinemann’s teshuva and it touches upon many of the things we have been discussing. Amongst these is that gram is measured as per ‘toch kedei dibbur” and also that , if you don’t disturb the light , it is gram kibbui and not kibbui mamash. Additioally, he brings down the discussion between ther Chazon ish and R’Shlomo Zalman concerning electricity- with R’ Shlomo Zalman wanting to be mattir ,as it is no different than opneing or closing a door. the chazon ish response was that a door is made to be functional both while open (to enter the room) and closed (to protect from the wind,etc) whereas a shut circuit has no other purpose. Rav Heinemann deduces frmo this that, in case there is a real purpose for the shutting of the current, it is muttor. This is how he allows adjusting the thermostat on yom tov because obviously, the heat in an oven (or the cold in a fridge) has to be shut off if you want a normal cooking (or cooling) and hence, the shutoff has a purpose and is also needed.
Anyway- the more one delves into these matters, the more one sees that there are so many variables that you just cannot draw universal conclusions and each case is unique.