Thanks for all the info. I do a combination of steeping/aging, breathing and I just did a hot bath in a crock pot for a couple of batches to try it out. It seemed to work great. I let them sit in the water for 6 hours, shaking every 30 minutes. Then I let them breathe for two hours, capped them and put them in a cool dark area to sit for longer. The water didn't get above 150. It seemed to have turned the liquid to the same color as if it had been regular steeping/aging for 2 weeks. Any negatives with the warm bath if it's kept at a certain temperature?
I've done the Crock-Pot steep several times with success. There is a ton of information on it if you google steeping e juice or speed steeping e juice. I think you'd also have success googling Crock Pot steeping e juice. A few years ago, there was a group of vapers, I think they were here on this forum, who tested the Crock-Pot steep pretty thoroughly and claimed to have tested the juice afterwards to make sure the nicotine content was not degraded.
They recommended putting your juice in baggies or unicorn bottles so the labels won't be ruined, adding water to your Crock-Pot, and putting the bagged juice in the water for about four hours. They claimed as long as you set your Crock Pot to the lowest setting, and leave the lid cracked open a bit, the water won't exceed 140 degrees, and the nicotine won't degrade. I've never tested the juice for nicotine levels after doing this, but I am sure I would have noticed if the nicotine content had been reduced. After I take the bottles out of the bath, I open them, squeeze the bottles to allow fresh air in the bottle, replace the lid, shake them very thoroughly, and let them rest a bit for a couple of days in a dark place until they taste like they're ready. While they are resting, I make sure to squeeze each bottle and shake it every day, at least one time per day.
Most of the time the juice is ready to go after I've done this, but some juices will require a longer steep after the bath. Just vape them every few days until they taste like they're ready to you.
Good luck!