Suggestion: Moving common metadata fields to a core sample description set

Would it make sense to define a core sample description set among the tables that is implicitly part of all of the metadata sets?
This way, changes to one of those fields in a data set would not propagate to the others without the need to edit the field in all of the different places, circumventing inconsistencies. All other sets would be extensions of this core metadata set.
A contra argument would be, that the proposed tables become more complex to understand.

Another unrelated suggestion would be to track the mapping to other standards more explicitly by splitting the "source" column into "source_var" and "source_set" to make later import/export mappings easier to implement/automate. If the same field is mapping to multiple sources, "source_var" and "source_set" would consist of multiple column/set names separated by semicolon: e.g. source_var: seq_meth;INSTRUMENT and source_set: MIGS_BAv5;ENA

In both cases I am not sure whether this worth the effort or whether the result is actually desired.

Cheers,
Clemens.