So, the proposal is too allow NLI's to be signed earlier. That takes an unenforceable oral commitment to a theoretically enforceable contract (though I don't see how it's enforceable against a party who has only limited legal capacity to sign a contract [a minor]; but that's a different issue).
A signed NLI means that all recuiting stops. As a soph or junior. We all know - from present experiences - that a coach can undo the NLI (theoretical enforcement be damned) and leave the kid in the lurch.
Want to make a coach/school responsible? Every time an NLI is signed, that is PERMANENTLY counted against the 11.7 - regardless of the player actually matriculating. (Perhaps an "injury" exception could be imposed.)
I fail to see how a HS junior (or soph) is better positioned academically, maturity wise, or experienced enough to make a life decision is opposed to that same kid a year older.
Take the risk of early recuiting and place that risk firmly on the school/coach (rather than the kid) and I hypothesize changes would be quick.