UDT dynamic Template Item Field

Referring to the new UDT functionality of 2023 R2, is it possible to parameterize with one or more internal variables the Item Name of a Derivate Template?
e.g. DBname.ARR[idx].ALARM where "idx" in the square brackets is the iterator.
I think this feature could be interesting in order to take full advantage of making the item name dynamic by instantiating it from a template, without the need to edit the json file.
Acting from scripting on the template Item field could perhaps be another way?
Many Thanks