Exported bodies are bigger in size than the original file

[Mannshoch]

I tested the "Export selected Items" feature (source STEP 242 destination also STEP) and had the strange effect, that the resulting size double than the original File.

What could be the cause of this?

Source File Schema (Inventor):

ISO-10303-21;
HEADER;
FILE_DESCRIPTION(
 ('',
'CAx-IF Rec.Pracs.---Representation and Presentation of Product Manufa
cturing Information (PMI)---4.0---2014-10-13'),
 '2;1');
FILE_SCHEMA (('AP242_MANAGED_MODEL_BASED_3D_ENGINEERING_MIM_LF { 1 0 10303 442 1 1 4 }'));
ENDSEC;
DATA;

Dest File Header (Mayo 0.9):

ISO-10303-21;
HEADER;
FILE_DESCRIPTION(('OpenCascade Model'),'2;1');
FILE_NAME('Open CASCADE Shape Model','2025-03-24T16:34:40',(''),(''),
  'Open CASCADE STEP processor 7.8','Open CASCADE 7.7','Unknown');
FILE_SCHEMA(('AUTOMOTIVE_DESIGN { 1 0 10303 214 1 1 1 1 }'));
ENDSEC;
DATA;

Goal was to reduce the Data not to increase it.
[edit] Tested also with v0.9.0