I would think that a significantly longer drying time would be needed. Lustrekote recommends at least 24 hours before even masking for any additional painting, much less a harsh treatment such as a heat gun at high enough temperature and close enough to the surface to tighten the covering. Just because a paint is dry to the touch doesn't mean that it has fully cured, and this takes time.

It's also possible that the color coat you mention hadn't yet fully cured before you put the Lustrekote on, making the situation even worse as an incompletely cured color coat will cause problems for the top coat adhesion, and the top coat will keep the color coat from curing completely.