Hi,
A Community post asked for an example of how to implement functionality similar to the 'Reduce to List' node using the Agg Ex node. Here is an example. This is NOT a drop-in replacement for the Reduce to List node as its configuration is slightly different (e.g. there is no need to include double-quotes around the Delimiter property value) and the default name for the concatenation of the ItemField values is 'ItemField-List'. There are may also be other edge-case differences in its operation.
As the data flow is built using Dataverse 3.1.3 you will need this release or later installed to import the data flow .lna file (attached in comment below).
Note also, this is a standard node rather than a library node.
Regards,
Adrian