
TheFinish |

For question 1, it's unclear. Pack Rat references mundane storage containers and vehicles. It'll be up to GM if Cheek Pouches qualify, though then we run into another problem:
There's no such thing as 1.5 bulk. We as players might envison it as such, but for PF2e there is only 1 bulk and 2 bulk. In fact, since you round down fractions, you can store up to "1.9" bulk in your Cheek Pouches already if you have big mouth, because 1.9 Bulk = 1 Bulk for the rules. So I don't think Pack Rat would apply. Or rather, it might apply, but 50% more bulk, on 1 bulk, is still 1 bulk.
As for the second question, I'd say maybe? Conceal an Object does say you Conceal the Object "on your person". Is inside your Cheek Pouches "on your person"? I'd say yes, but since the rules call out Interact to Store, maybe not? It's something you'd need to hash out with your GM.
But for me at least I'd allow it. If only because the idea of a Ratfolk using Silent Sting and then hiding the weapon in their very obvious cheek pouches, acting nonchalantly, is too funny to not allow.

Waldham |

Is it possible to store a lozenge in the mouth without activate ?
You Activate an alchemical lozenge by putting it in your mouth. It stays there, slowly dissolving and releasing its ingredients over time.
Are there need to retrieve with an Interact action to activate the first or second effect ?
Thanks for your future answer.

Trip.H |

Is it possible to store a lozenge in the mouth without activate ?
Quote:You Activate an alchemical lozenge by putting it in your mouth. It stays there, slowly dissolving and releasing its ingredients over time.Are there need to retrieve with an Interact action to activate the first or second effect ?
Thanks for your future answer.
There's no reason for the storage container of an item like a lozenge to auto-activate it or anything. I'd say a ratfolk PC can keep the wrapper on, yes.
I can only speculate that a GM may be fine with a 1 Action (and 0 Hand) cost to activate the passive part of such a lozenge.
Base RaW would be that you need to "put it in your mouth" as part of that initial activation, which is a discrete act, not a state. Meaning, super-RaW, a GM would require a hand to put the item into a mouth to start the passive.
The bite part is a bit less clear. A GM might require the lozenge passive to be ongoing first, or they might allow the ysoki to bite a lozenge w/ the wrapper still on.
Note that some lozenge effects grant Reactions, and as effects of the dissolve passive, one could never bite an inactive lozenge for its Reaction.