Question about Sony Rmt-Dslr2

hello, this answer might be a bit late. But i just used it for this. Set the camera to bulb mode, then press once like you would to take a picture to start and another time to stop. Worked quite well for me on my a6500.

Unfortunately, we haven't been able to test it. However, the question has been forwarded to our community so users with more experience can answer.