CD-RW with UDF requires full format first?

If I want to format a CD-RW to UDF, it blanks the whole disc.
On DVD-RW, the disc is not completely blanked, just at the beginning.

But each time I format a CD-RW, it blanks the whole disc. Isn#t that a waste of ressources? Is that really necessary?
Imagine doing the same with CD-R. The CD-R works fine without FULL preformat.

This happens in every available UDF version. 1.50, 2.00, 2.01 and 2.50.