I'm experimenting with implants right now. I found that the jockey gives a benefit of 250 shields regardless of my actual number of shields. So, if I have the normal 500 than 50% is correct. However, if I do things like equip bionics and auxiliary shield for 950 shields, jockey still adds 250 bringing me to 1200. Yes, I was trying to figure out if I could get 1425 shields while on a mana turret. No, no I can't.