Is that right that "[y]ou only have 30 minutes after opening a shipped fish bag to put them in the tank"?
Seems like every acclimation instruction I've received from an internet fish seller has strongly suggested that an hour is the sweet spot for drip acclimating and that has almost always worked for me.
An hour is at least 30 minutes too long...~15 minutes in sealed bag to temperature match, then ~15 minute drip...and you're done!