I think the implementation of the modelling version option is more recent, Quantum 2.03:
Axe-FX II Quantum Firmware 2.03 Release Notes
This version firmware allows switching between three firmware versions: Quantum 2.00, 2.01 and 2.02.
http://forum.fractalaudio.com/threa...ev-2-03-firmware-release.112395/#post-1343996
The previus version FW Q2.02 weights 2.723.715 bytes (size on disk 2.723.840 bytes)
FW Q2.03 weights 2.736.270 bytes (size on disk 2.740.224 bytes)
But must take in account that this difference in bytes not only reflects the implementation of the modeling version option parameter, in Q2.03 Friedman BE/HBE V2 models were added too.
Only Cliff knows the real impact in bytes of this feature