My own reading of the relevant text in the Mime spec is that use of 8BIT is
to be the same as 7BIT, but with bits that have their 8th bit on also
allowed. Since the reality is that old-style email doesn't deal with null
very well, then one would expect 8BIT to do badly also.
Different statement: RFC822 says sending NULL is ok for 7BIT, but broad
(mis)practise says it isn't. Mime says 8BIT is like 7BIT, except for the
larger set of characters. Don't plan on NULL working.
You say NULL problem of 7bit should be inherited to 8bit.
But, dependeing on implementations, 7bit is broken in various ways and
degrees.
Which defects, do you say, should be inherited to 8bit?
How many of it, do you think, will also be inherited to binary?
Masataka Ohta