>>85060622Two rules in play make this more confusing than it has to be.
As a general matter of course, an ing ending tends to replace an e ending in intensifying the last preceding vowel. Replace. Replacing.
To indicate that the ing ending is not intensifying that vowel, you use a double consonant. Flit. Flitting.
However, when you shorten a word into a diminutive, you still spell and pronounce that piece of the word as though it were still part of the whole. Collab is short for Collaborate or Collaboration. In this case, the ing is replacing the e at the end of collaborate to form collaborating, so no double consonant is necessary. It's just not necessarily intuitive when you shorten it to collabing that shortened from collaborating and follows those rules.
