A shortcut would be to wrap the "Insert Queue Element.vi" in a VI that have a Variant input instead of a string input. This way the typecast to variant is transparent (except for the coercion dot). In that VI there are two ways to flatten to string before calling Insert Queue:
Variant to Flattened String: the flattened string of the content of the variant is insert to the queue (no type descriptor).
Flatten to String: if the variant itself is flattened to string. The difference is that now the type descriptor of the content is also included in the string along with the flattened content. This can be handy to actually determine what is actually in the string when removing a queue element. After removing, Unflatten to a variant indicato
r visually displays the data content and is useful for debugging. Variant to Flattened string can then be used to extract and parse the type descriptor to typecast the content to its datatype.
Jean-Pierre