Depends on how wide/deep the cracks are. I usually use some solvent cement to repair those areas, though sometimes I can get the thin CA to wick into the cracks. If there is a stress point there, then, like in the above message I try to see if I can glue on some structural support if I can do so without changing visual appearance.
There are a few kit companies that make some pretty fragile kits. I know who these folks are, and try to use extra caution when building their kits.