Cant add much of value, 6 months, no problems.. but most running time does not crack 40 degrees cause I fill small guns directly (20 seconds?).
Have one larger bottle on a gun (hatsan factor), but I do the same, switch it off when it gets to 40, let it cool back down, switch on again.
Got some 1 liter bottles incoming, thinking of doing the same, filling them in intervals as to not stress the unit.