Preparing Bow String

I thought that this would be a nice upgrade.

It would be something like:

Preparing Bow String, preparations are lengthend for 10-20%.

Meaning that a standard prep, (24 sec) would at maximum take about 29 sec.

Or was my maths wrong?

Preparation and Stance upgrades would be awesome...

Can't be unbalancing seeing as they have the enchanting mods adding enough time for some spells to near to fully recharge before it wears off.