I've noticed two things.

For the Crystalline Flask, if you activate it twice, the particles on you will disappear, but you will still recover for both activated charges.

Repro Steps:
1. Buy Crystalline Flask.
2. Use 2 charges and watch your particles disappear.


And for Total Biscuit of Rejuvenation, there is no particle that shows that you have mana regeneration (little blue swirls).

Repro:
1. Put 9 in utility to get the Total Biscuit of Regeneration.
2. Use it, only green particles for health appear, no blue for mana.