Wood movement is still a problem with epoxy, but it depends on how you use it. To fill holes or even fairly large gaps, not a problem. Putting a rim on a 12" platter and it will have a problem eventually. When filling voids of say 1 or 2 inches there simply isn't enough wood movement in most woods to cause a problem. When you start getting up to the 10" and bigger range then you get into 1/8" seasonally on some woods but that of course depends on where it's stored and how much humidity changes in the area stored over the year. When I do decorative rings out of epoxy or Inlace I try to undercut the slot so the epoxy is kind of captured. In my tests what usually happens is one side comes loose and then over several years that loose area gets larger and larger. I had a 12" platter that I left an epoxy ring on the outer boarder. I cut a rabbit and then cut a slot in the inner side of the rabbit. Filled with epoxy and then turned away all the wood to leave the epoxy proud on both sides. It still filled the horizontal slot so I had a mechanical groove for the epoxy to bind to as well as the outer surface. It took about 3 years for it to show a gap. The gap would git bigger every year working it's way around until I could pull the ring completely off.