Yaso, a few comments:
Firstly, on this sentence: "This means that the necessary merges are personal choices."
This is, ultimately, the problem with public consultation in Brazil and many other democracies. We haven't yet created the right tools, both in terms of technology and process, to vet citizens contributions and actually sort them in the most refined, consistent and democratic way. What happens is that lawmakers, be them in the Executive branch, preparing a legislation proposal, or experts in the Legislative branch, will most of time put their own views and experiences in the vetting process, influencing heavily in the final product. I honestly don't believe in a democracy that the citizens contributions will go "un-vetted" in the process. If it was like this, then we'd see the craziest laws being presented and passed into Congress.
Secondly, I think we could reach out to citizens to all vet their own contributions, instead of purely leaning on technology to do this. What if we start approaching public consultation with a 2-prong strategy, where in the first place we collect contributions, and then we ask citizens to vet the best or group similar contributions together? What if we give them this power of refining their own work? It doesn't need to be a separate process or divided in different phases on a timeline. It could happen at the same time. Imagine you just put a comment in an article of a public consultation. When you hit enter a pop-up asks you whether this contribution could be grouped with another 10 contributions? That would be really good and it's a mix of both technology and people power.
That's it for now. I'll keep thinking about this and come back for more comments :)