Thank you for that explanation. So to be clear Simple commands are not supported within Shared actions like they are with advanced actions. Is that correct?
Not at all, they just will always remain the same for each instance of the shared action. It is not necessary for a command to have a parameter. In my last blog post with Shared Actions tips I offered an example of a shared action which had no parameters at all. That just means if will act exactly like the advanced action but has the advantage of being visible in the Library, and very easily to be transferred to other projects which is not the case with advanced actions. Have a look at:
http://blog.lilybiri.com/rare-tips-for-shared-actions