Revert "Make Flattenable not virtual"

This reverts commit acf70d926b986e57a9b66d3cf3bb5efaae9fbb02.
Revert "complete the sensor swapout"

This reverts commit c741479cf6272aabfea28c87c517772a917a1cb5.
Revert "revert to 4.3 sensors for testing"

This reverts commit bdaaeaf52092c497b82da3089ce68b145b45befe.
Update README