This simple mod allows you to add certain Power Armor torso mods with a lower level of the required crafting perks.  The mod/armor combinations are based on lore from FO4 and previous games with the reasoning that it would be much easier to install a mod on armor designed to accommodate it. 

Specifically:
T-45: reduces the requirement for the Medic Pump mod from Science! 4 to Science! 3
T-51: reduces the requirements for the Jetpack mod from Science! 4 and Armorer 4 to Science! 3 and Armorer 3
T-60: reduces the requirement for the Emergency Protocols mod from Science! 4 to Science! 3 and for Reactive Plates from Armorer 4 to Armorer 3
X-01: reduces the requirement for the Stealth Boy mod from Science! 4 to Science! 3

This way, you are encouraged to specialize your various Power Armor suits to do certain jobs, and can get these high-level mods much earlier if you do so.

Combine this with my Power Armor Diversification mod to give your Power Armor even more variety!

Compatibility:
This is just an .esp mod that changes the requirements for the specified mod recipes.  Anything that doesn't change those will work fine.