I got a bit tired of going to Audio Settings and MIDI Settings and selecting devices there every time I restart PD. I figured, I should be able to automatically examine the list of connected devices using [mediasettings/audiosettings] and [mediasettings/midisettings].
I'm still planning to do that but I found one inconvenience that limits how convenient my abstraction can be. If I connect a MIDI controller after PD has already been started, it doesn't show up in the Midi Settings dialog. [mediasettings/midisettings] doesn't return it too. So I'll have to restart PD every time. It's still better than having to restart PD and fiddle with the dialogs but I was wondering if it's a known issue with Pure Data. I'm using Mac OS 10.9.5 if that matters.