i've added a zerk to every carrier i've been into, and also drill a series of holes into the spacer to allow grease between the spacer and axle. (be sure to clean all burrs, inside and out, from the drilling)
i do not leave the inside seal out of the bearings, i pack them and replace both seals.
my reasoning for the zerk/adding grease is just to keep as much water/dirt out of the hole assembly, and for ease of disassembly if ever needed again.
it is not to keep the bearings lubed, the waterproof blue or red grease i pack in them and reseal has proven to last as is.
i've never had to re-rebuild a carrier i've already done !
leaving the inner seal out, hoping grease from the zerk gets into, and stays in the bearings, and not any water/dirt is a crap shoot at best, IMO
i would/have not added zerks to the swinger pivots, thats just another place for them to break/crack.
the inner end of the zerk ends up right against the outer race of the bearing, how is it getting around that press fit race and into the rollers ?
it takes less than a 1/2 hour once a year as routine maintainence, to pull the pivot bolt, end caps and bushings, inspect the condition of, and manually apply grease directly to the pivot bearings.