Ask what they still need to try
Ask what they have not been able to test. The answer shows whether more time will help or whether they need a hand with setup.
Use a simple rule
Decide in advance who gets an extension, for example one extension of a few days to anyone who has used the product. A rule means agents do not argue each case.
Offer help along with time
Suggest the one or two steps that show value fastest and offer to walk through them. Time alone does not help someone who is stuck.
Set a firm end date
Give the new date and say what happens when it passes. Vague extensions slide into months and leave customers surprised by a charge.
Follow up before it ends
Send a short note a day or two before the end with what they have tried and what comes next. Make it easy to subscribe or to say no.
Learn from the requests
Tag requests by reason. If many people need more time to finish setup, shorten the setup or lengthen the trial.