Reading your question, I think what you're actually after is a new condition type rather than trigger. You will use the existing sunset/time based trigger, and then need a new condition to check the status of your other device. This can be achieved using the Tuya API and is something I can add in the next few days.
In terms of triggering sequences from devices, someone else had asked about this, and right from the begging I had hoped it would be possible. I've been in discussion with the Tuya support team and while it doesn't seem possible directly via their API they have provided some information which might solve this. I need to spend some time picking through the info to see what will or won't be possible and will get back to you.