Third Tier competition for starters. Get players involved as soon as possible. I’d support a Super Rugby A comp along side a full Super Rugby U20s.
100% agree with this, this could be a perfect solution as well as following in more the NRLs footsteps, possibly with Harold Matts and SG Ball type competitions, whether this is done with Super Rugby teams, Shute Shield teams or others I think just having a larger system for teams and the sport in general, if I was to create a pathway it would look something like:
Continue normal reps until U15s, then U16, U18 rep teams/Academies (Can play games during offseason, or otherwise) then as Ghost mentioned a U20 Super Rugby comp, gives young players a pathway at a higher skill level than Colts but not risking injury or hindering development playing against grown men when the kids aren't ready, as well as a Super Rugby A comp similar to NSW cup where plays can come back from injury, those who are ready can have their first chance against grown men.
Rugby Australia just needs to figure out an actual pathway to make rugby a career, at the moment the case is too much if you aren't good enough at 17-19 years old you can't carve out a career, losing too much talent from Schoolboy rugby to NRL and just those who can't go anywhere.