I regularly take my knives down to 10 - 15 deg. I have a couple in the 5 - 10 deg range. Most of the time that doesn't cause any problems, except that you have to be careful with the tip once it gets thin. As Cliff was always fond of saying, geometry cuts. You have to match the steel and it's intended purpose to the knife. "Better" steels let you go thinner, if that's what you want. Harder steels will also. Sometimes you just have to get to where you do some damage until you find the limits of that steel, heat treat, and geometry. I've done that with D2.
I take my BAD's down much thinner than my regular AD, as they are harder. I use the regular AD's for wood, and the BAD's for hunting. Both work great.
I think it's worth pointing out that no steel will *never* be damaged, whether it be rolls, chips, or whatever. Any knife can be broken or damaged. My very first Busse was a Steelheart E. I still have it, it's one of my favorite camping knives. I tried a test when I got it in the mail - set a beer bottle cap on a 2x4 and chopped it in half with one stroke - it rippled the edge, with the factory bevel. It was easy enough to sharpen out on a stone, but that goes to show that if you exceed the limits, you will have damage, doesn't matter what the steel. I will also say that INFI is far less susceptible to damage than most other steels.
So yes, you can cut mild steel with it, but there will be some deformation - it's inevitable.
I've got both Fehrmans and Busses, and like them both. I think both are excellent steels that will last a lifetime if used sensibly.