The check costs depend on the platform (and probably generator too). I don’t know of the performance costs, but that’s because I personally find that even if it were performant, there’s at least one issue that I run into often enough to make it not worth it.
I still highly discourage globbing for the reason that files may appear in your source tree that you do not intend to build. The main case I’ve run into is that during conflict resolution in git, the other versions of the file(s) in conflict are named ${base}_${origin}_${pid}.${ext}, so if you try to build in the middle of a conflict, you’re going to glob up these files.
Another reason is that now the addition/removal of a file is not present in your build system diff, so tracking down “what did you change?” in debugging reported problems can be harder since there’s no evidence of accidentally added/removed files in a normal ${vcs} diff output.