Thank you for your inquiry.
Yes, you can keep a laptop on the stage during the OnStage performance. However, you cannot use main electricity. (refer to 1.3.4)
BTW, I have two concerns about your performance. Could you give us more detailed information to clarify them?
1) What method will you use in sending videos from the Raspberry Pi to the laptop?
Please refer to the rules 1.4.2. Junior teams are never allowed to use Wi-Fi at the competition venue. There is no exception on that.
2) Are there any plans to show that streaming video on screen with a projector?
At this moment we do not know how long the cable to connect to the projector is and how the AV equipment is arranged. We cannot promise you to be able to offer what you want.
I hope everything goes well for you.
Shoko Niwa (2018 OnStage TC and OnStage OC chair)