Total number of bytes Nero Express reserves for overhead on a DVD+R?

I asked here why Nero Express was increasing the size of my compilation (from 4,700,371,958 to 4,700,766,208 bytes) when I tried to burn it to a DVD+R. Apparently Nero reserves some unspecified amount of space for overhead/table of contents (henceforth refered to as O/TOC), which can render useless any careful splitting of large hard disk partition image files for back-up to DVD+R, using the maximum amount of space available to that medium.

In my situation, Nero added 394,250 bytes of O/TOC to my compilation - making it impossible to write that compilation to disc without overburning.

I would greatly appreciate it if someone could explain the O/TOC and how it is handled in Nero.

  1. Does the O/TOC size differ, in each unique compilation, or is it always a fixed number of bytes regardless of the size and number of files to be written
    to disc? For example, in my scenario above, Nero added exactly 394,250 bytes to my compilation. Does Nero always add this number of bytes for the O/TOC?

  2. If the O/TOC size does differ for each unique compilation, then what specific criteria is used by Nero to determine the number of bytes to reserve?

  3. Can this criteria be laid out as a general formula for users to refer to when deciding how to split large files into uniform sized segments that will span multiple discs?

  4. If it is impossible to know the precise formula Nero uses to size the O/TOC, is there at least a known, MAXIMUM number of bytes Nero can reserve for this purpose, and that users can take into consideration when deciding how to split large files to back-up on DVD?

Many thanks,