What do you think about “forcing” athletes under a certain age (say 14 years old, just as an arbitrary number) to enter a variety of events outside of Athletics “championships”?
For example, we have a fair number of local meets but only one age group championship indoors and one outdoors; at those local meets should younger athletes be “forced” to enter a run, a jump and a throw? Additionally there are school meets so quite a choice.
The “force” is, of course not really enforced but more encouraging athletes and coaches to enter one running event (say 60m or 150m), one jump (long, high, triple is only allowed after a certain age), one throw (shot indoors, more variety available outdoors). The entire meet event list is covered between every 2 meets and that means, indoors for example, there are about 4x a season that “your” event is planned on the schedule.
Related to this are somewhat informal competitions for “triathlons” as well using the same results, adds a few more ribbons but allows those who are good but not the “best” to be competitive as well.
In terms of training: Speed/Power base. I think for as long as possible as I have witnessed a number of individuals locally who in running middle/long distance that seem to forget about speed/power near completely and it only takes a couple of years until they can not keep up with what was their peer group any longer.