I've done about 8 5 gal batches on my mash and boil, and the only time i got the E4 code is when i left it unattended and had a massive boil over. I use it for biab with a wilserbrewer bag and am happy with the mash and boil. The robobrew would be better for a non-biab all grain, but I don't see a huge upside for biab. I definately strive to keep it simple and try not to sweat the small stuff. Works great for me.
This is exactly what I was looking at getting the M&B to do. Could you elaborate a little on your process and setup? Do you full boil no sparge or sparge? Do you mash recirc? With this setup would installing a dip tube work?
Thanks