Haste potions, among other potions, have been distributed in the Garda during the recent Black Army plot. The anti-potion stance should be re-evaluated, and I don't believe it's been something that's been in place for a while—seems rather new.
It's been accepted by the Garda and DMs who have ran NPCs in the Garda that as long as the potion doesn't have a permanent visual effect (ghostly visage, invisibility, shadow shield, shadow form), they are acceptable. Haste potions would fall under the same category as "combat enhancements" like animal ward potions.
This has been the only way that Garda have been allowed a slight chance at combating troublesome outlanders, let's not make this a thing.
