Just keep in mind I have tested several casting devices...NONE have zero lag, it just won't happen with this kind of tech. The Microsoft casting dongle has the lowest latency I have found in testing.
For very in close flying, where space around the drone is at a minimum? I wouldn't use any casting dongle, but in normal flying where you have time to react....It shouldn't be a problem. Remember that you can cast directly to a smart TV or similar device without using any casting device. The tablet has it built in, but even doing that there is some lag. I will see if I can do that today and take a screen shot of the stop watch app...casting from the tablet to a TV. With and without the MS dongle. I am curious to see if there will be a difference.
I'm actually impressed with the setup. Will have to fly with it to see how things go in the real world, but it's promising.
Appreciate any testing you're willing to do. Do you have an HDMI splitter? I'm also wondering if it's possible to connect two devices using a splitter. Thanks.