Nazyura's utilities were written for the older (pre-ROYL) models. IIRC, those had a single-byte checksum at a different location.
If you use Pete Disdale's checksum utility, as follows, then most of the MODs should sum to 0.
chksum2 -32 *.MOD > MOD_chk.log
Don't be surprised if a few of them don't sum correctly. I don't know why, but this seems to happen even on good drives.
You may find that some MODs contain a "NOT INIT" text string. I believe that this means that these have not been initialised at the factory, and are therefore not used.
BTW, MAVR_R reports the names of the MODs as "ID_size.MOD". For example, the name "02_0005.MOD" refers to MOD 02, and is indicating that it occupies 5 sectors in the System Area (SA).
FYI, MOD 02 is targeted by HDDHackr. HDDHackr enables WD's Scorpio drives to be used as replacements for other brands of HDD (eg Fujitsu) in Xbox applications. It does this by editing the model number, serial number, and capacity information in MOD 02 (and the firmware version in MOD 0D). If you know which byte to modify, then you could use it to make the IDLE3 changes via an UNDO.BIN file.