Is this made of horsehide? If so it will take a bit longer than cowhide. I have several hybrid holsters and overall I find them to be the best most comfortable holsters I've ever owned.
Here's something that might help - oil it, much like you would a baseball glove. I use saddle oil on mine (bought it at Tractor Supply). It helps reduce the squeaking too.
I also rubbed mine with lanolin on the skin side. mine was a bit rough and the lanolin softened it up a bit without making it the least bit floppy. And I ended up slathering it on and heating it with a hair dryer to get it to soak in. Now its VERY nice.
I couldnt find leather products that were JUST lanolin, so I used some of the wife's breastfeeding cream... Lansinoh... in a purple tube if you need to find some in the baby section of the store. Its like vaseline, but made from lanolin instead of petroleum.
As said above, mine got more comfy in about a month. Part that needed the most break in was the lower front corner, as I wear mine at 3 o'clock and that's where I needed some walking and sitting flexibility the most. I saddle soaped mine a few times in the first couple months and that helped.
Mine never got that comfortable, but it did improve. I don't doubt the folks who say their's is comfortable, it just doesn't work for my body, where I position my holster, and my firearm.