Ultra Studio 4k & alpha channel keying

My setup

I have a atem TVS.
3 SDI Cameras
1 Computer feeding replays back in via an HDMI input.

I want to feed graphics out of Softron OnTheAir express that has also has alpha channel via an Ultrastudio 4k

The ultra studio has OutA & OutB but I only see 1 HDMI out.

Since I only have 1 HDMI available input & 1 SDI available input - Can I feed the video feed out of the OUTA via SDI and the alpha out of the HMDI (or the other way around - Doesn't matter to me ) OR does both the video & key have to come out of the OUT A&B SDI?

You can only output key/fill signals via SDI. Since you only have one available SDI input on the Atem TVS, you will need to purchase an SDI-to-HDMI mini converter to connect the second UltraStudio SDI output to it.

Better than the above would be to use the SDI-to-HDMI converter to connect one of the cameras so you can connect both SDI outs from the UltraStudio to the Atem.

Spoke to BM today. They said that I can output via the HDMI for the Video source and the SDI can do the alpha channel. Does anyone have this and give it a try?