Well, there's also a difference between L4 and L5. L4 is a little more relaxed for me, it's more for competitive experience. Level 5 the routines become significantly more complex and require greater strength and technique. You can't really just fake it through the routine. When a kid doesn't have the ability to kip, usually their swings are weak too. You don't even have the chance to work on routine amplitude and flow with connections. Same with the other events, if power is weak it is difficult to go over the table relative to doing the handstand flatback in L4. The floor routine is longer and more complex with two BHS at the end. It becomes more important for safety and progression that the kids are able to do the skills competently. Even more so for L6. If they are promoted to L6 struggling with L5 (any of the routines), it's going to be a huge struggle to compete at that level. They will be facing many competitors who are essentially much more prepared than they are. What we have to realize is in some places compulsories are getting high 9s on ALL four events. To get them on some events doesn't necessarily mean the kid needs to move to the next level. They need to master all skills at the current level and have the skills safely and competently (in terms of technique, not to just throw and build bad habits) for the next level.
I would be more willing to start a kid who had most L4 skills competing, just to put them in the competitive atmosphere and hopefully improve the weaker skills. But if they could not do multiple L4 skills (FHC is used in L5 too...also pretty similar action to kip...if a kid cannot do the FHC then they will probably be weak at kipping at that point) I can't see moving them to L5. To me that's two different things. Sometimes you bring kids onto your beginning team training without them having every skill, because there is no other appropriate place for them to work at that level.
I would be more willing to start a kid who had most L4 skills competing, just to put them in the competitive atmosphere and hopefully improve the weaker skills. But if they could not do multiple L4 skills (FHC is used in L5 too...also pretty similar action to kip...if a kid cannot do the FHC then they will probably be weak at kipping at that point) I can't see moving them to L5. To me that's two different things. Sometimes you bring kids onto your beginning team training without them having every skill, because there is no other appropriate place for them to work at that level.