I had thought that the load cells as used in bathroom scales suffered more from the effect of creep and distortion?
The frame for mounting will be stainless steel. Again, to visit some of these hives means a 5 hr return journey, the hives at times will be left for a fortnight, but if the honey starts to flow heavily in that period then a revisit to super sooner will mean more honey collected in a box that we can more easily harvest (rather than the bees packing it down in their brood boxes).
I am not familiar with the Japanese wasp, in New Zealand we have German wasps, which can be a problem. Generally entrance guards, which reduce the size of the hive entrances, are sufficient but still requires a strong hive for defence. If there is a size diffence then certainly this could work - size is the principle for keeping queens out of honey supers, it is also used in pollen trapping where the bee can fit through but not the pollen grains on its legs.
Can i expect issues using the HX711 premounted? - it was suggested to me that it might be more temperature sensitive than other chips like those I mentioned??