Convert a 7D CR2 with DNG Converter 5.5. This gives certain values of metadata such as color matrices & white level.
Now convert that same CR2 with DNG Converter 5.6, and this gives different values of such metadata. (That is reasonable. After all, 5.5 was a beta version as far as converting 7D CR2s was concerned).
Now convert a DNG output by DNG Converter 5.5 with DNG Converter 5.6. (You can use the DNG Converter on old DNG files, of course). The metadata in the new DNG remains with the original 5.5 values.
Why not, as least as an option, generate the latest metadata? Don't we, in future, (at least as an option) want to be able to use the latest DNG Converter to bring our old DNGs up to the latest state?
Retrieving data ...