My two cents is that it depends if you're going through it for the speed run or just to finish. If you just wanna finish it, then you're fine. The usual goal of the life pot usage is to save it for Ballos as a safety net for the last form if you're going for the easy war. However, getting past the Heavy Press isn't hard without a life pot. There are the many ways of restoring a buttload of health along the way, and I'd say that if you wanna beat Ballos, you need at least 40 health. So I'd make it past B2 ASAP, do the B2-B3 jump trick for health if you need it. Go along B3 normally and try to save as much health as possible. When you finish Press and need health, go to the statue room and see if you can get any heart clusters. When facing Ballos, try not to take any damage from Form 1 and a minimum for Form 2. Don't worry if you die 1000 times. Hell will make you it's bitch.