This lengthy 1993 report by the Ad Hoc Group of Governmental Experts To Identify and Examine Potential Verification Measures From a Scientific and Technical Standpoint has a good deal of material with regard to a BWC verification regime, including a description of concerns with regard to declarations.

For example,

information provided… would need to be made available to all States Parties. Concern was expressed that this could create confidentiality problems for some of the categories of information already suggested as the subject for declarations.

That issue is familiar, but this one was new-ish to me:

…releasing the names of personnel employed in a declared facility may result in attacks by animal rights activists or terrorists. Industry may be unwilling to provide commercially sensitive information if it was to be made public. It may be possible to prevent such problems by careful definition of what information is required to be declared, and by ensuring the information is strictly controlled under the BWC.