[Fuyu no Sora]

Originally Posted by Icarus

Spoiler:

No, that is canon knowledge. In the A's manga (ch2 I believe) it is said that Raising Heart drains a mage's power constantly. Yuuno comments that most mages would be completely exhausted to the point of collapse after a few minutes worth of drain from the device, but Nanoha is somehow able to manage it on a daily basis, and even trains during her daily routines. She even says something along the lines of "it was uncomfortable at first, but I think I'm used to it now".

If anything, I reckon the limiters are in place not just to balance the ranks, but for Nanoha's benefit as well, given that her body is suspected to not be in complete health from the accident and the continual drain by her Intelligent Device.

Spoiler:

However it is also stated that the strain is part of a magical program, made to benefit her in the long run.