I have a similar set up. I have a Loadmaster Trailer out of Florida. It is as Red explained also. I don't use the buddy bearing since it has to be taken off to apply grease to the inner zirc fitting. Once grease is applied, the old grease is pushed out from the back of hub to the front. I simply put a dust cover that has a rubber seal on instead of the buddy bearing. All that has to be removed is the rubber seal on the dust cover. I also put grease all over the nut holding the spindle to keep corrision away. The only problem I have had is that my inner seal on the hub will allow grease to get out and therefore, allows some water in. I constantly "push" the water out by adding a little grease to the zirc fitting every few trips. The water comes out with the old grease. If you put grease directly in the buddy bearing in this type of set up, you are not getting grease through out the hub and you will experience a failure down the road, literally.
I have tried to replace the hub seals, but they always seem to leak grease. Maybe I need a new hub?
My opinion from personal experience....