Nice episode. Am I to assume the decoy shuttle that was destroyed by the Klingons is supposed to replace the original (i believe) scripted scene of holographic ships projected from the Enterprise?
In general terms, yes. The "duplicates" were just described as "Xon's electronic manuever" which relied on K'Sia linking minds with Ilia...and it still left a dozen ships chasing the Enterprise to the Homeworld. (referencing "Writer's Work Draft" dated Jan 1978)
The end of the second act was Kirk beaming down (with two Klingon guards) and issuing orders to Decker to "implode the engines" rather than surrender the ship. This seemed more dramatic.