So $40 for an audio adapter is dumb (DJI if you read this, its true). I was wondering if anyone else had just bought a 3rd party USB-C to 3.5mm and had the same results? I see a lot on amazon for as low as $7.99 and I'd rather go that route if it works.

Third-party adaptors don't work, period.
The Osmo Pocket's adaptor is actually a separate analog to digital convertor and not just a port.

Hi, thank you for bringing this query for us. We do not recommend using any 3rd party accessories for the Osmo Pocket since there is a possibility that it might not work or it will just give you problems. Therefore, we do recommend using compatible accessories for the said unit. Thank you for your kind and understanding. Cheers!

Which 3.5mm jack will this work with-- TRS, TRRS or either?   I need to purchase mic, and want to make sure I have correct cable.  Thanks

djiuser_ZeDvzz950NsM Posted at 8-8 16:10
Which 3.5mm jack will this work with-- TRS, TRRS or either?   I need to purchase mic, and want to make sure I have correct cable.  Thanks

Also, does the mic need to be powered? Thanks again

djiuser_ZeDvzz950NsM Posted at 8-8 16:18
Also, does the mic need to be powered? Thanks again

TRS only. Can be either powered or not but the adapter input is very fussy and only a few microphones seem to give an adequate level output. The mic can also be mono as although the input is TRS, the output from the Pocket is mono. Look around the forum posts. There are plenty on the subject.

Looks like its true. No other adapters will work and the DJI is constantly out of stock. Frustrating and long wait.