The first rule seems to be the way it is, right?
USA Shooting has had over 8 months to add in their own "interpretations" or notes as to whether they will use the ISSF rules. As you know these additions (in red) become the USA Shooting Rules.
You are also correct that the "current" USA Shooting rules are the "2016" rules which are really 2012 and 2014 documents. So in rifle, we're really 3-5 years behind the curve. In fact at Nationals they were running under "2017 USA Shooting Rules" ... there is no such animal. And they were were trying to enforce ISSF interpretations that they only had in their head ... nothing in writing. Technically they could not have disqualified anyone.
So as understaffed as they are, they have punted, kicked the can down the road, etc. and have just said current ISSF rules for competitions.
(And I heard yesterday a major player there is resigning ... all the more understaffed)
Here is a comment I made in another post that would allow them to quickly do this instead of posting (whenever the heck they get to it) another "rule - book":
While I applaud the use of the ISSF rules:
A) The version should be stated as ISSF seems to have "rule change parties" quite often. (current is 2017 V1.1 --- I think)
B) Maybe a USAS versioned "Common Match Director Bulletin" (CMDB) is a quick easy way for USA Shooting to accept/not-enforce certain ISSF rules
C) Where USA Shooting seems to be hard over on non-written rule interpretations of their own, these should be included in the versioned CMDB
The CMDB would be a document that they could refine as the quad rolls along and only be a page or two. (OK ... maybe 3 or 4, but still better than having someone wander thru a doc version of ISSF adding red text)