Modern LIPO batteries don't "like" to go below 20% especially repeatedly. Most people use the 20% rule of thumb and this will greatly extend overall battery life. I've got some LIPO batteries (not Phantom) that have in excess of 150 charge cycles on them with no significant "puffing". Granted the 150 charge units aren't as potent as the new ones (I've noticed a performance drop in the 75 - 100 cycle range) but they aren't deformed and still take a good charge. The keys to non-Smart batteries (Phantom batteries are ultra smart IMHO) is to keep them well balanced, don't store them at more than 40% charge remaining, don't store them in a HOT environment, don't charge them unless they are room temp (I use a small soft sides cooler with a cool pack inside to help get them cooler quicker when on the job), don't let them get too cold, don't try to fly them in very cold temps (I preWarm my batteries in cold weather) and don't discharge below the 20% level if possible.
For transparency I'm VERY new to DJI products (about 2 weeks in now) but I've been flying RC for 4 decades and have a crazy amount of LIPO batteries that I maintain for my other RC aircraft.
Just my 2 cents.