Dave's made some good observations and asked some good questions that as far as I can tell haven't really been addressed yet, so I'm going to pile on and expand on Dave's comments with some of my own.
The convention body approved the proposal for 12 at-large members. The Bylaws Committee minority report proposed a reduced-size regional representation plan; it was voted down by the body. The majority report proposing at-large delegates was adopted by a healthy 2/3 majority. What I'd like to see here is a good faith effort to implement the will of the convention body before we pre-emptively try to revert this thing to some kind of apportioned representation.
Not that apportioned representation worked that great for the past ten years. This seems to be a case of an abstract idea of how things 'should' work clashing with practical observations of how things actually work. Or don't.
It is possible for SLEC to occasionally spend a great deal of time rearranging furniture in a way that doesn't actually change much of any importance (ask me how I know...

). Before we continue the discussion re all the different ways we could arrange direct representation, let's please back up and be sure we understand what problem we're trying to solve here.
Some years ago a previous SLEC said "just having a County Coordinator on staff isn't enough, we need to create a department of people who can recruit county chairs and help build our organization and its leadership from the ground up". So we stood up an Affiliate Support Department whose specific area of responsibility is supporting our county affiliates. And from my POV the current ASD has been doing a pretty good job of that. What I've seen so far is that the ASD is making more support available than most counties know what to do with. To the extent that individual county leaders reach out to SLEC members for help, the main help we could give them would be to refer them over to ASD!
It's not clear to me yet what support a county's leadership would need that would not be available through the ASD. That brings us to the questions around 'representation': what that actually means in this context, and why direct representation is being assumed as necessary for each county. What kinds of questions are we expected to answer that ASD couldn't answer? What kinds of comments or complaints are we supposed to hear that ASD couldn't hear?
Overall, I'd like to see us using a more organic and natural style of collaboration and leadership. Every policy decision we make, every behavior we try to legislate and enforce, will at best only ratify something that could've happened naturally, and more typically will interfere with a free market's delivery of better solutions. My suggestion would be that we compile a list of the new SLEC membership with at minimum our SLEC email addresses, and then maybe phone numbers also for those who are willing to provide them. Make that list available to every county CEC, and invite them to call anyone on that list they prefer if they feel that they need to reach out to a SLEC member. Each of our members should be able to answer questions from individuals or connect that person to someone who can. We'll end up building a robust relationship network based on personal knowledge and trust, instead of being based on 'official' assignments.
We are not a legislative body; we don't make laws and try to run other people's lives. We are an executive board responsible for the health and success of an organization. Not everyone needs access to the executive board in this or any other organization. We need to see ourselves as a board of 16 at-large members and officers 'representing' primarily the will of the 100+ delegates who (a) set up this structure, and (b) elected us as individuals to populate it. We need to focus on strategy and goals for growing this party and winning elections.
I'm holding off the bigger matters until after national for the sake of our delegates; for now we just need to get through the initial organizational meeting. But come June, we'll have some serious strategic work to do. Let's give the at-large structure a real chance, and then see what needs tweaking, if anything.