Okay so there's a little bit more backtracking that I do in this episode (granted it was to find out if I could not use Beat in Skullman's stage and permenately keep him by my side), but I do at least find the secret for getting the Balloon Adaptor.
Truth to tell, they might've been pointless in the end, since you get both adaptors in Cossack's lair anyway, but hey we got to fight both Crashman and Waveman by finding those adaptors first (so I say it was still worth it). Anyway, in this episode, we finally travel to Cossack's lair and go against his minions.