How many of you grease your own trailer axles?

I have a HQ15 Black Series travel trailer and I am in the process of converting the hubs to an oil bath bearing set up. Due the amount of miles traveled and weight #5200. From what I been advised its good solution to the joys bearing packing.

https://www.etrailer.com/Trailer-Bearings-Races-Seals-Caps/Kodiak/XLPROLUBE1980KIT.html
I'd be worried about failure. Normal styles can tolerate a little misuse as long as you check them at the beginning of the season. If you lose a seal in an oil bath.....You've got nothing. I suspect that we wouldn't get the same quality set up that you'd see on a semi. I'd carry a spare hub and hope that a bad bearing wouldn't take out the spindle.......I do like the idea though.