two things I’ve been encouraged to do are:
feed the bees a tonic of 1 part water and 1 part white sugar and the juice of fresh garlic, 2 litres each week for three weeks before winter
in spring and summer, every three weeks or so move old brood and honey frames (up to two frames in total) up to the honey super, make sure you don’t move the queen too, and replace them with new frames with foundation, that way there will be a rotation of frames
both these measures will help prevent a build up of disease or pests
I’m not sure if this could be done with the Flow hives.
hope that helps