Is this a plat stress or phenotype difference

I have slow growing plants Speculated to be called by the weak light
the main plats are 11 weeks old and look healthy other then it looking stringy
the Stain is Purple haze
Grow medium is CoCo
Nutrients are
2ml Cal Mag
2.5ml micro and Gro
1 ml Bloom
with PH at 5.7 to 5.9
all three plands get the same treatment other then I only topped one and the other two I topped once with LST
Any thoughts on how the two plants with LST will flower or will the stems hold up now they they are so long?


This is the start of the plant and the plan on how training went