In vanilla Skyrim, the Alteration perk "Mage Armor" increases the power of armor-increasing spells like Oakflesh, but only when you are wearing clothes (i.e. you are not equipping any pieces of light armor or heavy armor). This mod simply removes that requirement, allowing you to enjoy the increased potency of armor spells so as long as you have the perk.

Obviously not balanced, but this will let you wear modded armors in a mage-style playthrough without needing conversion patches or making edits. I found that other solutions, such as flagging all armor in the game as clothing, was kind of a drastic solution to an otherwise simple change.

If there are any issues, please feel free to leave a comment. Please keep in mind that the perk in-game will still say that you must not be wearing armor. This was left unchanged to minimize conflicts with perk mods as much as possible—please verify yourself by checking your armor rating in game.

Compatibility
In vanilla Skyrim, the flesh spells will check your level in Mage Armor and if you are wearing any light/heavy armor upon casting, and then apply Mage Armor's bonus effects if applicable. This means that Mage Armor perk itself doesn't really do anything—the spells themselves do the heavy lifting. This mod essentially removes the armor check on each individual spell, meaning that it should be compatible with perk mods that don't heavily edit the Mage Armor perk.

In terms of individual spell mods:

• SimonMagus's Mysticism: COMPATIBLE (patch included in the FOMOD)
  

Please leave a comment if there are any particular mods that you would like a compatibility patch for. No guarantees though.