Does 3 lock need all the synth skills?

So, on Amino apps there is this formula:

• Synthesis Success Rate = (50 + Skill Equip Synthesis Boost + 2 * TEC)/Equip Synthesis Lock Penalty
  
• where, Equip Synthesis Lock Penalty = number of locked characteristics²/2
• So for 255 TEC and 3 lock, Synthesis Success Rate = (50 +510 )/4.5 = 124 %
• So, do we really need the Synthesize Equipment and technical synthesis skills at lock 3?
• I mean, at 255 TEC and 4 lock, Synthesis Success Rate = (50 +510 )/8 = 70 %
• And at 5 lock it's even lower.
• So I know one needs the skills later, but do you really need them at 3 lock? I can invest in other skills to level up my character and then max those skills later...

 

last year, just the 1st skill was enough for 3 locks

 

So which skills need lvl10 for 4Lock nowadays?
Just the 1st and 2nd?