Will updating from 4.3.0 to 4.3.1 waste any data or possibly ruin any previous work that has been done within a previous project or should a 4.3.0 project be compatible with 4.3.1 and transition smoothly?
those are the changes for the 4.3.1
either way its always good to backup 
also this
"These QFEs eventually get rolled into the hotfixes and major version release updates that we provide for all, but until those updates we want to make sure that they are available to the select users who need them.
Please be aware that QFEs should only be used by the individuals who are experiencing the select issue; they do not provide any additional features or improvements for other users."