Are there any 3rd party accessories that allow for external power and also plugging in a microphone?  

I've seen some 3rd party accesories that bring the power directly to the main camera module but I'm hoping that we'll see a 3rd party accessories that brings an additional USB C port that would allow for you to plug in external power & an external microphone while still using a module so you can have a SD card plugged in as well.

Am I dreaming to think that this is possible or that someone will come up with something to make it possible?

Power to the main camera module is easy since its aligning the 2 pins responsible for passing power to the modules internal battery - nothing more.
For instance, you cant pass data through a Type-C port to the camera module alone - the connected display or power module is in effect the 'brains' of the combination, and hence handle all such tasks.

When it comes to providing external power as well as using the port for data input (external mic), in theory I cant see why not, but in practice I'm not sure it will work. One could adopt the use of a type-c splitter cable of sorts and connect to power and a mic, but the possibility of interference is there due to the mic input and power feed through the same channel.....

IftiBashir Posted at 2-13 14:03
Power to the main camera module is easy since its aligning the 2 pins responsible for passing power to the modules internal battery - nothing more.
For instance, you cant pass data through a Type-C port to the camera module alone - the connected display or power module is in effect the 'brains' of the combination, and hence handle all such tasks.

Right, I hear that.  

I just wish there was an adapter that would work similar to how it did with the Osmo Action 1.  Plugging that into the USB-C port and getting a 3.5mm jack out and a USB-C for power was awesome and was hoping for something like that for the Action 2.   (https://www.amazon.com/CYNOVA-Ac ... ation/dp/B08J7J98BZ)

Unfortunately that doesn't work at all with the Action 2.

Hello there WICreekPaddler. Good day and thank you for reaching out. Since this is a 3rd party accessory for the DJI Action 2, I hope that you will get the best recommendation from our fellow DJI members  who uses the said accessory on the said DJI camera and where to purchased it. Just a reminder that DJI does not recommend for you to your 3rd party accessory on your DJI Action 2 for compatibility and reliability purposes. There is a possibility that these 3rd party accessories will be able work properly. However, since it's not tested by DJI we cannot guaranteed the safety of the said 3rd party accessories if it will work all the time with no issues when in uses. Thank you.

DJI Stephen Posted at 2-13 20:29
Hello there WICreekPaddler. Good day and thank you for reaching out. Since this is a 3rd party accessory for the DJI Action 2, I hope that you will get the best recommendation from our fellow DJI members  who uses the said accessory on the said DJI camera and where to purchased it. Just a reminder that DJI does not recommend for you to your 3rd party accessory on your DJI Action 2 for compatibility and reliability purposes. There is a possibility that these 3rd party accessories will be able work properly. However, since it's not tested by DJI we cannot guaranteed the safety of the said 3rd party accessories if it will work all the time with no issues when in uses. Thank you.

Thanks DJI Stephen, do you have a recommendation in regards to powering the DJI Action 2 with an external power bank & being able to use an external microphone at the same time?

Thanks for your time.

Well just for kicks I did test a high quality USB-Splitter that went from power to power/headphone.  

It would power the device when nothing was plugged into the headphone portion.  When nothing was plugged into the power and I plugged a microphone into the headphone portion, it would come up and read the microphone properly.  However I could not have both plugged in, if I did, it would only supply the device power and would charge it.  I have to hope that potentially firmware can adjust this on how power/microphone comes in from the same port at the same time.  

I'm crossing my fingers and hoping someone from DJI can confirm at some point.