Where Cover Art?

Hi all

Flac files, as us knows, follows the Vorbis Tags system included in block 4
Recently Vorbis has established the possibility to include picture files by 
means of 2 Tags:  COVERARTMIME AND COVERART.
To work therewith is quite easy.

However Flac stores picture files in block 6. The edition (to add and to 
modify Tags and pictures simultaneously in two separate blocks) becomes a 
difficult and tedious task in comparison with the easiness of Vorbis 
handling .

I think the current situation is an error. No Tags type acts this way, 
except Matroska.
Would not it be better for Flac to follow Vorbis approach, including covert 
art in block 4 and to abandon the insertion of pictures in block 6?

Another question. Where a Tag should be included with song lyrics?

Regards. Santiago