Actually, I am in position similar to the OP's, so I would like to expand a bit on the subject:
- many industrial cameras can be interfaced using the Gige Vision protocol.
- this protocol is very low-level, and each frame is received with minimal meta-data.
- so storing the pixel values is mostly the programmer's responsibility.
- so every person facing such a camera ends up defining his/her RAW format.
- still, it would be good if the images produced could be read by LibRaw, and all the programs built around it.
- and it would hardly make any sense to add to LibRaw a routine for each file type produced by each version of each software written by each new person.

So the bottom line is:
- given LibRaw's developers experience with RAW file formats, could they point out an existing one that is already handled by LibRaw with which newcomers could comply with minimal hassle? (as the OP pointed out, DNG seems to have been designed just for that, but I have no idea how hard writing DNG files is).