Core CC:DA Public Space

I recently came across a situation where I desired to record some family biographical information associated with a specific copy of a title in our collection. It seemed appropriate to record this in MARC 21 field 545 "Biographical or Historical Data." When using this field it seemed wise to also deploy a $5 subfield "Institution to which field applies," given emerging dynamics of systems that are directly derived from OCLC WorldCat records, are continuously synced with OCLC WorldCat records, or are resident in consortial systems subject to overlay by consortial member peers. At present, none of these apply to my institution but I thought using $5 might help in some way to "future proof" the edit. In attempting to do so however, my ILS indicated $5 was not valid for field 545. I have confirmed this in the MARC 21 documentation. I recognize that field 545 likely arose to serve the needs of the archival community. And since the collections and associated records managed by archival institutions are typically unique, then there usually is not a need to specify the institution to which a field 545 applies -- it is the very institution that created the record and holds the resource. But for the use case that prompted me to use it in a bibliographic (rather than archival) context and the dynamics articulated above, does it make sense to pursue efforts to add $5 as a valid subfield to field 545? I recognize that $3 could serve a similar purpose, but I do not think the means to configure local holding data or match & merge arrangements would be as sympathetic to the use of $3 as they might be to $5. 

So, is this something worth pursuing on behalf of the descriptive cataloging community? This would be the first time in my memory that CC:DA would originate a MARC paper, although there have been papers from communities represented in CC:DA's membership. Are there particular stakeholders within CC:DA that would be interested in weighing in on developing such a paper? (EIther yea or nay, or in the drafting or feedback process.) 

In particular, I thought RBMS might find this of interest. My institution can't be the only one with rare books having family associations that might warrant being recorded in the bibliographic record. If peers here have alternative solutions, I would also welcome those for my personal toolkit (and evidence that my prospective proposal is unnecessary).

Regards,

John