My own personal take on lock picking in F4. 

I originally tried Harder Lockpicking by th3t3rr1bl30n3, but I found it problematic for two reasons:

1 - the actual "sweet spot" wasn't tight enough for my liking, and the picks seemed to break too easily;

2 - It seemed to me (later confirmed in F4Edit) that his values were "backwards", and the bobby pins would break easier on novice levels.  This would result in 7 or 8 broken pins on novice level locks (they would break instantaneously), but somehow they would be more resilient on Master level.

Now, novice level locks should be relatively easy to pick, but if you're not careful you can break a pin or two.  Difficulty will increase incrementally, and by the time you get to "master" level stuff, you need to be very adept indeed.

Compared to th3t3rr1bl30n3's mod, the end result should be less brittle bobby pins, but a tighter sweet spot on the actual lock.  You will have to be more precise, but you will get a bit more breathing room to do so.

I've briefly tested it in game, and master level locks are indeed quite a challenge to pick!

I recommend using Fewer Bobby Pins and Stimpacks, which compliments this mod nicely.

Cheers!