We put in a combination of the 12X12 and 12X36 (30X30cm & 30X90cm) to create a pattern in all but the bathroom. The bathroom was done in the 12X12. It is under all the cabinets, banquette, etc. Only the bathtub and front fresh water tank are on the sub-floor.
There are items secured through the click into the sub-floor: stove, frig, banquette, water pump, etc. None of the cabinets. They are secured through the walls and ceiling.
We left it floating and its been in two years now. No issues with movement so far. We do keep it heated in the cooler months.
This will be the first year its kept under a roof while stored.