Variations in MP pools of elementals, fellows, etc.

A couple of years ago, I discovered that elemental avatars possess a finite amount of MP. However, during my testing I found that the same type of elemental would use varying amounts of MP. For example, on one call AirSpirit used 2999 MP; on a subsequent call, it stopped casting after using only 2811 MP. At the time, I chalked it up to one of several variables which might affect an elemental's total MP, such as day, time of day, moon phase, or the like.

However, when attempting to determine whether or not the Hydra Jupon set had to remain equipped for fellows to receive benefits, I first tried to account for MP usage and was surprised to find that fellows seem to behave the same way. On one occasion my fellow, set to Soothing Healer, cast 771 MP worth of spells. On another, she stopped casting after only 680 MP worth of spells, and would not even cast Poisona on me after that. I had already considered that my fellow's announcing she was "ready to go" did not necessarily mean 100% MP and had waited several ticks after this announcement to ensure a full MP pool.

Even with the Ibushi Shinai +1 and the full Hydra Jupon set (which I didn't have at the time anyway), the maximum variation in MP should only be 70 and this is clearly not the case.

There are several complicated explanations for these behaviors, but the simplest is that there is a bug preventing a fellow or elemental from using their full MP pool. This is not such an issue for elementals as, during normal play, their MP limit is rarely reached (although it's far more likely now in Abyssea), and in any case they can be instantly resummoned. However, for fellows, who have a limited MP pool to begin with and who are often counted on for survival, the issue becomes more dire.

I would appreciate a developer response to this thread. If no explanation is forthcoming, I will consider making an official bug report.