Whether an insurer's order to appoint an expert, or refusal to do so, causes irreparable harm and is therefore appealable immediately.
Such an order does not, by itself, cause irreparable harm and is not immediately appealable.
Under the applicable procedural rules, an incidental decision is only appealable if it is capable of causing irreparable harm. A mere order for expertise, or a refusal to order expertise, does not meet that threshold.