I think the answer for the general public is the same as for the HG, PG, and LD populations: individualized work at their own pace and with appropriate interventions and supports as needed, in line with mastery teaching principles. (This is very like what the RTI model was supposed to create, but its implementation, at least in Florida, has been nearly the exact opposite.) This could be accomplished in school settings without excessive additional cost through district-wide block scheduling, the abolition of grade placements, at least for academic subjects, the consistent and appropriate use of pre- and post-tests to assess readiness to move on to more advanced topics, with both curriculum compacting and additional practice and explanation available to all students as needed, and the appropriate use of technology. Live humans with appropriate knowledge and training would be used as mentors and facilitators, to lead, guide, and enhance group discussions, whether those discussions were happening face-to-face or remotely, to help give additional support and extension to those struggling with mastery of a given topic or those wishing to explore it in greater depth, and to help develop and refine writing and logic skills.
Unfortunately, bureaucracies tend to perpetuate the status quo, even when everyone knows it doesn't work, so I'm not holding my breath.
