I felt that the spawn rate of Legendary enemies was too high, so I've decreased the spawn chance for each difficulty by a factor of 5.

• Very easy    0.25 => 0.05
• Easy             0.5 => 0.1
• Normal         1.0 => 0.2
• Hard            1.5 => 0.3
• Very hard    2.0 => 0.4
  

Due to the somewhat immeasurable nature of this patch, I consider V1 untested.

If you want more control over the specific spawn rate or you want to stop Legendary enemies entirely then I recommend this mod: Customize Legendary Enemy Spawning.