Have wax moth, but not much trouble with SHB... I use an upper entrance year round. It is only a little bigger than an inch long and 3/8 deep, but the bees seem to appreciate it, and I also seem to have cleaner comb in the honey supers than I used to have... I wont even get into wintering, mostly because I dont want Robo to see it and come slap me. let me just say that an upper entrance seems to be benficial HERE. You will have to determine if it is beneficial THERE. As stated, it should not hurt on a strong hive while it is being weighted.