In Powertracks I think the option is labeled 'Smooth Audio Cuts' .. but it is in the Edit options.
Not sure how this works with the 'Punch In' option.. which was mentioned in the original question.

I usually record the new track to a separate track, then re-assemble it later, and in that case the above mentioned option works well.

Enforcing this behavior on Punch In; not sure

My earlier post was more a solution for 'after the fact'


Make your sound your own!
.. I do not work here, but the benefits are still awesome