I do not think it makes sense to think about this in the same terms as serialization for storage or transfer.

Since we don't do our own ASN.1 encoding for example we rely on the backend to do it for us. Some backends don't support it so it may be desirable to e.g. do your crypto operations with a backend that provides key material but can't do ASN.1, and then store it using a backend that does support ASN.1.

For various reasons including that I am definitely against adding those kinds of serializations to the actual keys.