How are you defining the metadata - via an import, Designer, DDL?
We are defining the metadata via embedded Teiid programming ( DDL).
We don't automatically quote based upon the table/column names, rather if you have a using table/column names that need quoting, then use the name in source option:
create foreign table tbl (...) options (nameinsource '"quoted name"')
Using a Designer or dynamic vdb import should automatically handle the necessary quoting.