Maybe I sound like coping but I genuinely think Pantalone will be playable guys I swear. The traveler doesn't know Pantalone is the mystery man working for dottore (yet). He is also big and influential to snezhnaya's economy as the guy who runs northland bank.
The tsaritsa would 100% be atleast on amicable terms with the traveler later on. It would make sense that as someone serving under the tsaritsa Pantalone could give traveller financial support and just do his job
Traveller would hate his ass but I feel like they are more likely to be in more amicable terms with him than someone like signora and dottore whether they like him or not.
Based on what dottore said, Pantalone could just die a natural death once the last of the elixir runs out so I doubt he would die by getting killed like the other unplayable harbingers for plot and he seems comfortable to his job as a banker so I don't think he has any motives to ever betray the tsaritsa (unlike arlechino who would if the house of hearth geys affected)