keep the ice anchors for the hubs as far out as you can, with-in reason. it helps to put a better side pull on them than having them close. having them close pulls down more than pull outwards, so they don't help as much from collapsing hubs.
the ice shaving from making holes should go to the inside and on the side the wind is blowing on. i just use my feet to slide it over to it. if you use a sled, you could put that with what ever weight you have in it and keep it on the windward side flap.
you can go to harbor freight or where ever to buy a grommet kit and install some on the flaps so you screw in one ice anchor per corner and one in the middle of them.
you should check the anchors you use and make sure they have the large washer on the shaft so it can touch the grommets so they can't slide up on them.
maybe you can have them added if they don't have them. take them to a metal fabricator if you don't weld.
i like using the motorcycle hold down straps the best instead of the ratchet straps for pulling the hubs out.