I just hatched out my first clutch of python eggs (ball python) and I incubated them in a modified hova-bator. What I did was trashed the bottom of the hova-bator and made my own so that it was about 14" deep. I did this by making a wood box 14" deep and square to fit the top of the hova-bator. Then I went to Lowe's and got 1" thick styrofoam and lined the box with it. This gave me enough room that I believe I could incubate about 20 ball python eggs, but I think that would max it out. I don't know what the size difference is between bps and carpet python eggs, but I would imagine it would be about the same. My bp eggs weighed in at about 100g each.
This worked ok for me, the only bad part was that I live in a trailer and the temp in the room varied SO much that I had a hard time keeping the temp in the incubator between 86F and 91F. But if you had a room that stayed about the same temp I think it would work great!
The way the thermostat works is there is a little knob you turn one way to heat it up, and the other way to cool it down. So you can't just set it at 90F and leave it.
As far as humidity goes, I used a rubbermaid container (do not put any holes in it at all) filled about half way with vermiculite that was wetted so that it just dripped a little bit when I squeezed it in my hand. Over the couple months they were incubating I added water probably 7 or 8 times. Sometimes just spraying a little, other times taking all the eggs out and adding quite a bit of water to get it back to dripping when clumped. I weighed my eggs about 1 to 2 times a week and that determined when I added water. If the eggs stopped gaining weight, or started losing weight, then I would add water. I started with 8 eggs and last Sat. I got 8 healthy baby ball pythons hatched out and looking beautiful! And I was constantly opening the incubator and their rubbermaid container because they were my very first clutch and I just couldn't stop myself from always wanting to see them. So that wasn't a problem. I hope this answered your questions. Feel free to ask more questions if you have more.