You know I just pack all bearings (automotive mechanic by trade) the old fashioned way with the palm of your hand forcing it into the rollers thoroughly ,using the correct grease for the paticular application .I dont pack the cavity in the hub full .As has been said ,that does nothing .Boat trailers I have serviced ,and have done alot of those, most of the time had water damage in one or all of the bearings. Never did i see one that had overheated bearings from the hub cavity being full ,having bearing buddies installed ,ever.
If overpacked the grease does get past the seals it does get on the shoes.
So definatley with buddies you have to know how to grease properly.And of course with regular bearings the same thing applies . I have not seen overheated bearings in a hub where the bearings had grease,or the hub had grease in it together .My experience packing and servicing wheel bearings is about 30 years now .I would have to see it to believe it as they say.Pay careful attention to not mixing different types of grease as my earlier posting
touched on ,that causes the grease to break down .you can check with major suppliers of greases,such as valvoline and stalube ,there websites should explain the makup of different greases and there intended use.