Why go against the math?
Personally with 44, I split against 4 only with a +1 or better, otherwise I hit. This is contrary to computer analysis, but it's a close call regardless.
Yes it is a close call. But why not do what is best even if it is ever so slight? Why would you not split 4/4 against 5 or 6 on a DAS game? Only reason I can think of is if the C was way high, it should possibly be doubled. I don't know what the index number would be though.
The EV on a 4/4 split is even better against 5 & 6 rather than against a 4.