You and your publisher do not have aligned interests. Your interest is to be read, because you being read gets you money. Your publisher wants a horde of gold to sleep on so they can rent it out. The result is that publishers have the utmost contempt for libraries, but authors love them, because the libraries can direct readers to books outside of publisher control.
Codifying CDL is never going to happen because it's a loophole big enough to drive a The-Pirate-Bay-branded truck through. It would be easier to abolish copyright. With first sale on physical goods, it's obvious where the first sale rights end and infringement of copyright begins. With digital, literally everything is an infringing act of copying[0], so any rule of how many copies can be made (e.g. "one to one") needs full-supply-chain enforcement. It'd be very easy to cheat the CDL system without even generating any evidence that cheating had happened.
For example, in the IA case, even when IA was enforcing their own CDL rules, the libraries they had partnered with weren't as careful. There were several libraries that were caught not taking the physical backing copies of loaned e-books out of circulation, none of whom were actually removed from the CDL program. I mean, the physical book doesn't stop existing when you loan out the e-book, you just have it on faith that we pretend it's been shoved inside the wires until that e-book copy expires.
What we actually need to fix libraries' ebook programs is collective bargaining and compulsory licensing programs. We already have this for radio: there's a part of the copyright office that decides how many fractions of a penny to charge a radio station every time they play a song, and as a result, radio stations can play whatever[1]. The current way ebook lending happens with libraries is through Overdrive, a private corporation that acts as a platform for trading DRM license files around, but because it's private, it all happens with consent of the publishers. Libraries have been turned into a glorified "Netflix of books" because the publishers can play games with what parts of their collection are available for rental.
Instead, what we could do[2] is the radio thing. In lieu of a formal licensing agreement with a handful of consenting publishers, you have a collection society or government office that sets the e-book rental rates and handles payment. Libraries that want to rent out e-books can do so using whatever technology works[3], even with scans of orphan works if necessary, not just one particular e-book vendor's app that only works with officially delivered files.
And while I'm suggesting copyright reform ideas that might never happen, we should also ban copyright assignment.
[0] Or at least the Ninth Circuit says so, and they've never been wrong about anything, right?
[1] Though in practice, they only play like five songs, but that's Clear Channel's fault - the record labels don't get to say no here.
[2] with the consent of Congress, yada yada
[3] In practice this would almost certainly have to mandate DRM to turn the rental copies off at the end of the rental period, which is , but that's at least something that can be enforced by a third party.