I have a (2020) Teracube 2e. I see on the spec page Teracube - The Sustainable Smartphone With A 4 Year Warranty it lists a “headphone” jack. Is this output-only? I’d like to use trrs plug for a full headset (earphones+microphone), is this possible?
Yes - regular Android compatible earphones+microphone are compatible with Teracube 2e’s headphone jack - you will be able to use the microphone for calls.