I also remember reading about the theorized micro black holes. The fraction of a millimeter in diameter to quantum scale. If we were somehow able to create a process to reliably produce holes of micro size we might be able to send a small probe into one.

I keep coming back to this whole endeavor might be pointless as not even light can escape, how would we retrieve any information? Even if we somehow were able to get some info how could we guarantee the information is in a complete state? Maybe a lazer broadcast of info till right before the event horizon if the probe was strong enough to withstand the gravitational extremes. We might just get an understanding of how close probe x could get before destruction.

I guess if we could consistently reproduce black holes we could send enough probes to retrieve enough information in parts to understand more than we do.