Split VFO not holding settings

It is the slightly lesser than 2 evils situation because it complies with our premise of making transmit function under positive user control after a radio state change.  

For example, you are in split and operating.  Then you change bands and operate someone else in simplex mode (a radio state change).  You may not change bands back to the original band you were working split for a while.  You change back and persistence makes slice B the transmitter.  Since you did not directly control the state of the transmitter, you forget that the transmitter is on a different slice and end up QRMing a different frequency.  

The transmitter is put on the active slice after a band change to prevent the possibility of QRM.  If you want to operate split again, the operator has to make a change to the transmitter state (an example of a positive user control operation).  There is a use case for leaving it in split mode too, but as I noted, this is the slightly lesser than 2 evils compromise.