Size of boot.sdi is now 319 488 bytes: http://www.mediafire...oot_sdi_312.zip
The interesting stuff is that some metafiles only need to have some of the first bytes present. And some of them are not read at all. But since their reference can't be removed from $MFT, their occupied sectors can be filled with 0's. Namely $MFTMirr and $Bitmap are not read at all. $MFT and $AttrDef are not modded at all. For $UpCase only the first sector needs to be present. As mentioned before, the $Boot can be reduced to 1 sector (IBL not needed). The $LogFile only requires the first 8 sectors to be present (rest can be 0's). However the size of the LogFile can't be reduced from its current size of 262 656 bytes. Now the most interesting bit is that some metafiles can be cross referenced, meaning they can occupy the same sectors. This will be true when certain sectors are not read, or their content are the same (like with the 0's). In this boot.sdi, as much as 3 metafiles are located on some common sectors. The $Secure metafile effectively only takes 1 sector (rest can be 0's). It is entirely located inside $LogFile, and because $LogFile can't be shrinked, I did not bother much about its size.
If the $LogFile can be reduced in size, it is likely that the total partition image size can be reduced to the crazy size of 73 216 bytes!!
This must only be considered as research and a PoC. It works, but has not been extensively tested.