codemastr, it would be up to the user to make sure the data he sends through /msg via &binvar is appropriate. This should be obvious. You can send Good Data and Bad Data with standard %vars, as is (empty, too long, cr, lf, etc)... you will be able to do the same with &binvars too (null, too long, etc).
The point is, with &binvars you can preserve the freshness of the message and all its space-padded goodness, and alter or display this data as you please.
The only difference between "binary data" and "plain text" as far as mIRC is concerned, are 3 control characters that cannot be displayed as text (or formatting). Null, CR, LF. The other 253 characters can be displayed and handled just fine.
- Raccoon