Could have sworn I already suggested this...

[Namine]

Munak, Bongun and Yao Jin only drop Speed Pots if they are the race track version of the monsters. Namin? is certain that the normal version of those monsters will not drop them.

Authoritative Badge is also an important item that Namin? missed... afterall, people farm these specific movement up item for WoE, and used the effort to go all over the world finding insect monsters for gargoyle cards, then go to payon to mine badges and so on... gargoyle card maybe a bit harder, but the badge should not be overly difficult. Sohee is not exactly a tough monster, and the rate for them dropping the badge is relatively high too.