42 percent is the best it gets. following it to the letter
Hmm,
What skill is your potion making and enchanting at?
I have only tried this with 100 potion and 100 enchanting, and with the 5/5 +20% perks, and the "beneficial effects on potions you make are 50% more" perk.
I also had 4 items with +25% potion making.
The key here is that when you take the fortify restoration potion, that also increases beneficial enchantments on your apparels (but only when they are first put on).
So, make sure to take off all your apparels, look at your fortify potion apparels, note the % increase, take a fortify restoration potion.
Look at your fortify potion apparels, note how much it increased (if any).
If it increased, make a new fortify restoration potion (this should be stronger than the first one).
Take off your clothes, note their %, take the new potion you made, note their %.
Let me know if this helps? If their % increases and by how much.
Make sure that the restoration potion effect timer doesn't run out.