I have Waaave_Pool set up on a Raspberry Pi 3B+, with a small monitor in the case. It is delightful. I would love to have the output appear on the small in-case monitor as well as via the HDMI out.
The idea is it would be a tiny device monitor while the main output would be to a projector. I can achieve the same effect with an HDMI splitter and small monitor, but it would be nicer to use the little display in the case.
Have any of you fine folks attempted this, or know how to go about it? I appreciate any help or advice you may have.