Reminds me a fair bit of the BabyLM challenge. It would be good to give them a shout-out and see how this challenge differs.
> Directions we think are wide open ... Curriculum learning
BabyLM and offshoot published a pretty convincing body of work on exactly that (which suggests it's not particularly relevant to LM training).
As I read your page, I really felt like the brevity-thoroughness tradeoff went the wrong way.