From Leonstar0 on the forums:
And another one, which is definitely a bug.
It is possible to duplicate mana, by shooting mana with the mana blaster at a mana pool.
The mana pool has more mana in it then what was shot at it.

Standing at 1 block range, tried it from all cardinal directions in survival with a noncreative mana tablet.
All items were spawned in visa creative.

This is not a graphical/client glitch/desync, as I had a secondary empty mana tablet to measure how much mana was left. (was using f3-h-shift to measure durability) and had reloged. both with the secondaty tablet filled and unfilled, the mana remained.