Would like additional metadata about the contents of the CIF file that would help speed up the parsing of the file.

audit_syntax.case_sensitive_flag would be true if (A) all CIF reserved words are in lowercase, (B) data names match the case given in dictionary named in audit_conform, eg., atom_site.Cartn_x, (3) all keywords and data names appear at the beginning of a line, i.e., no leading whitespace.  (3) could be a separate flag, but they all need to be done for speed.

audit_syntax.fixed_width would be a space separated list of data categories where the data values are in fixed width columns.  And example would be the atom_site and atom_site_anisotrop tables in mmCIF files from the PDB.

With the above knowledge, UCSF ChimeraX can read a mmCIF almost 3 times faster.