I bought a new Scamp
in 2010. It has nearly 10K miles and I've never pulled a wheel. I was gonna grease through the "E-Z lube" but when I pulled off the rubber cap, the grease that was at the cup on both wheels looked brand new. I placed the caps back over the hubs and kept on trucking.
My wheel's arent "loose" (checking from top to bottom for 'play'), they spin freely and do NOT heat up on the road. I have adjusted the brakes
once. I do not full-time and am not on the road continuously. I do occasionally pull 500-1000 miles round-trips. When not in use, I do keep my trailer under a carport and on jacks and spin the wheels as I walk by periodically year-round. I travel "light" on the trailer so there's a huge safety margin on my tires/axle from the factory specs....that DOES make a huge difference on wear-n-tear.
In my opinion, what Dexter recommends > pull the wheels and inspect bearings once a year regardless of the miles- to me is a JOKE! I feel the "average" user stands a MUCH better chance of contaminating the bearings/grease and/or over-tightening the wheels doing this every year. If I'm totally wrong, time will prove it out. 6 yrs/10K Miles and counting.