It doesn't matter how 'naturally' elastic Lemaitre is, he would lose it all employing a heavy weight program (stiffness). Carl Lewis was the prime example of this (ran slower when Tom Tellez introduced weights into his program at the backend of his career).
It's a known fact that the elasticity of muscles & tendons diminishes massively (regardless of who it is) when lifting weights. Shinkage of the collagen is a secondary limit on muscular elasticity. So, the price of high muscle tone/strength is shorter, tighter muscles. Shorter, tighter muscles produce less force. Far MORE damaging, shorter, tighter tendons produce less energy (elastic stretch/recoil).
Lemaitre would have to sacrifice his top end (elastic elements). His 60-100m stint would increase.
And let me just assure you of one thing, Joe Defranco's training gym in New Jersey or West Side Barbell in Ohio aren't ever gonna produce any World class sprinters, lol.
Even without weight training Carl Lewis would out lift Lemaitre. And I believe Lewis ran his better times in the 100 and long jump at a later age around 28-30 years old.
Leamitre is not strong at all, never was, and this was confirmed. The weights he used is less than what the female athletes were. 99.9% of sprinters lift heavy to develop power and almost always run faster times.
Italy's Michael Tumi recently ran 6.51 in the 60. Looking at his body type an judging by his thighs, shoulders and trap muscles - he is doing a lot of explosive olympic style weight training. Now, Tumi does not have the top end speed like Lemaitre, but imagine Lemaitre with that kind of power combined with his top end speed...BUILD ALL QUALITIES OF A SPRINTER. You have this old fashioned thinking that one cant complement the other. How old are you sir?
The two gyms mentioned woud build Lemaitre's power and strength and improve his start out of the blocks and help him hit top speed at 40-50 meters rather 60 meters in a 100 sprint. They are known to help collegiate football players get ready for the combines. Lemaitre is regressing because, like you, his coaches know nothing about true speed development and working on Lemaitre's weaknesses. He wil never lose his natural elasticity if his training is properly monitored - stretching, plyometrics etc..
.Its a long term process that should of started 2 years ago.
PS: Do you think sprinters who take ped's take it to be faster? They take it to be stronger. Taking ped's without strenght training has no benefit. The strength developed carries over to speed when trained properly. Ben Johnson was a 600 pound squatter at his peak and ran his fast times. When he got busted and got off the ped's, and his strenght diminsihed, he couldn't crack 10.3. Lemaitre does not need to squat 600 pounds but he should, like any elite athlete, be able to move double his body weight (deadlift/squat). This is where he is severely lacking and what is holding him back, especially at the start.
hwell: