Lockout transfers support from primarily muscles to primarily skeleton.
There is more muscle tension shy of lock out, but there is more force required to pull a lever to full lockout.
Use both techniques if you're worried.
"...strength is built one recovery day at a time..." -OMP
"Do not change shit up during a training cycle." -Sandbox
Best PL total: 1020 - 350/265/405
Current total: 925 - 315/245/365