I was just reading your post on the other thread about this situation.
Personally, I would have to say no. If you need to, find a reason (my numbers will be off, age groups don't work, etc?). It just doesn't seem like a good idea to revisit this scenario.
These seem like extreme behaviours though? Is there more to this boy than just "wild child" syndrome? You don't mention how old he is, and I wouldn't want to jump to conclusions here... but the finger-in-bum-to-smear-poop is something that sets off warning bells. Is there a possibility of ADHD or some other such thing? That would make for impulsivity (screaming, lack of good decision making skills), and "all over the place"-ness. It doesn't sound like you take issue with the parenting skills or methods, as you still have care of the little brother.
I have nothing against children with alternate behaviour situations (have cared for ADHD before) but it is vital that you have the proper coping skills in these matters. In my experience, there is still a negative mentality towards "behaviour" kids. As such, parents either deny to themselves that there is something that needs to be dealt with, or they attempt to cover up or make things seem rosier than they are. One of my previous parents hid the fact that their child was on a daily medication, until I actually confronted her to say "what is going on here?".
It sounds like she is buttering you up, trying to win you over in order to find care in August. I would not go for it.