When you use "Use Default When Unwired" you cannot change what the default value is. The default value is always 0 for a numeric, false fro a boolean, etc. If in your cases, you only want to update certain values and leave others the way they were, you should have a shift register that is passing a cluster of all values. Inside your case statements, use Bundle by Name to modify just the elements you want and then outside the case statement, use Unbundle by Name wired to individual indicators. Attached is a very simple example.