[Question] Why do we need a tf if ask & tell would not need it?

[TheEimer]

When instantiating SMAC only for the purpose of using the ask & tell interface, I still either need to write a wrapper for my target function or just give SMAC a dummy function, both of which is not exactly elegant. I assume the reasoning here is that when users actually provide a runnable tf, they can continue with the standard execution in addition to ask & tell. I bet this is not the most common usage of ask & tell, though, and likely super confusing to new users. How about relaxing that constraint by simply issuing a warning? Something like "Instantiating SMAC with out tae runner - this means you will only be able to use the ask & tell interface."?