Where can I find the appropriate arguments/parameters to use with the BleAttrMetadata() function used in many examples in the BL65x User Guide, as I only see BleAttrMetadataEx() listed which appears to have different arguments/parameters?

The BLEATTRMETADATA () function is intentionally not documented in the BL65x Extension User Guides for our BL65x series smartBASIC modules, as it is preferred that the ‘EX’ variant BLEATTRMETADATAEX () is used going forward. The two functions are primarily the same, however, the EX version enables more functionality with the nFlags argument as compared to the FlsVariableLen argument in the deprecated BLEATTRMETADATA () function. The non-EX version is still supported to ensure old apps using it still work, including the code examples referred to in the user guide.

If you are looking for specifics about the BLEATTRMETADATA () function, such as the arguments and returns specific to that function these can still be found in the BT900 smartBASIC Extensions User Guide (pg 228), or BL600 smartBASIC Extensions User Guide (pg 110).