I think the risks and difficulties depend on the way your body heals to some extent. It depends on the amount of scarring on your uterus - whether your body makes a lot of scar tissue, or not. Scar tissue is hard to work with during surgery, I guess. But generally, if the pregnancy goes well, I think you should be all fine!

My mom had 8 c-sections, and while the recovery is no picnic, as I'm sure you are aware, it didn't get worse with each one. Seven of those pregnancies, surgeries, and recoveries went very smoothly. She did run into trouble in her last pregnancy, because the placenta adhered to a scarred section of uterus, and grew through the uterus and into the bladder. (placenta percreta - pretty rare). This lead to major hemorrhaging, hospitalization at 19 weeks, and emergency delivery and hysterectomy at 28 weeks. (My brother is healthy and well and almost 10 years old now, and mom is fine too. )

So there are risks with multiple c-sections, but they are relatively rare, and in our case, happened after 7 surgeries, whereas you are talking about 4. I would be willing to bet that all will go very nice and smoothly for you.

All the best!