In total 4/7 of the Adansonia seeds have sprouted. Germination is typically rapid with a good percentage or prolonged with a poor percentage so I'm going to assume no more will sprout. The seedlings have been growing well. I noticed the one that I planted in the deepest pot (25cm depth) is growing the fastest. Their taproots were about 10 - 15cm deep when I transplanted them. They sprouted less than two weeks ago!
They have been growing very well outside. Temperatures range from 14C at night to 32C during the day. Humidity has been quite high and seems to be averaging around 80% but dropping as low as 55%. They receive full sun all day. I put them in a small plastic greenhouse every night. This is more to make sure that they don't get damaged by animals then worry about temperatures being too low. I'm sure they would be fine left out but I'm a little paranoid.
The potting mix is about 1/4 sand, 1/4 clay, 1/4 manure, with the remainder being a mix of potting soil and whatever else I had laying around. I water whenever the surface looks dry. There shouldn't be any problem with rot because the soil is well drained and temperatures are warm.