Instead of selecting Double, Float and DateTime DataItem Nodes, these two scripts try to look far ValuePrecision Property in Byte DataItem Node. This is caused by programming error on line 40 of these two test scripts where the Node to be tested is selected with

var browseRequest = GetDefaultBrowseRequest( Test.Session.Session, monitoredItems[0].NodeId );

which results in Byte DataItem Node being always selected. The correct way to do this would be to select the Node with

var browseRequest = GetDefaultBrowseRequest( Test.Session.Session, monitoredItems[i].NodeId );