Just to add my two cents on this one. I have been flying drones for years...tried all sorts of tablets (Android only) and found all of them not bright enough....yes they work, but you end up trying to figure out how to get around the oh, not so bright screen. Some options:
Spend the $$ and get a TRIPLTEK tablet. Full Android tablet, including the ability to take a cell sim, so you can actually use it as a phone to get data in the field, 1200 nit screen, huge battery, built like a tank, no sun shade necessary. Use it with all your drones. Plenty of horsepower for any apps you want to throw at it.
Go onto Amazon and pick up a refurbished Samsung Note 8 and use this as a dedicated flying device. Super bright screen, but small-ish. I have found in the hot Hawaiian sun, this is the next best thing to the TRIPLTEK. I think the Note 8 was their brightest screen. Make sure you put the display settings on AUTO, this is the only way to get it to its brightest it can output.
IOS...iPad....never used one, so can't say, but herein2021 and others use them just fine. I imagine it would be ok to look for a used one, that would still work ok.
DJI Crystal Sky. Don't go this route with the Autel Explorer app. Yes, you can make it work, but the CS is locked down and you will most likely need to root it to get it to do what you want with using the Explorer app. Not worth it and DJI refuses to update the Android operating system on them. (I had the 5.5 one, sold it)
Nvidia Shield....I had this one too, sold it. Not bright enough.
Samsung tablets...not bright enough
Huawei tablets...not bright enough
Amazon Fire tablets...not bright enough...WAY not bright enough
However...if you use a sunshade, you could get away with just about any tablet. I have been down this road, so to save you time, money and frustration, it's TRIPLTEK or Samsung IMHO. You need the high NITS to combat the sun. There is NOTHING worse than being out flying, and the sun hits your screen and you can't see a thing...been there, done that.
Wait. There is another option. Do you like flying with FPV goggles? I don't, because you are cut off from the surrounding world, but no sun glare to worry about.
You can go with a cheap Chinese tablet that has HDMI out, and then use an HDMI goggle to view the screen. Here is one example:
What do you do if your tablet doesn't have HDMI output? Simple solution to this too...depending on what you consider simple: You DO NOT need HDMI output on your tablet or phone to send the Flying devices screen and screen share it via APP to your screen of choice also running Android, OR if you are just using FPV goggles, you would use an wireless screen module, supply power, connect both devices to the same Wifi and share your not so bright tablet to your goggles...lots of cables, but it works fine. iOS or Android. Notes in the description.
Or this video: (just pretend he is using an Autel Drone...same principal) 
I don't know how I missed this when I viewed this thread!
I purchased the Skyview Cobra X goggles which have a hdmi input connection. This seems too easy. If I understand this correctly. I need to do is purchase an hdmi wifi screen mirroring dongle and power it using a battery bank, plug it into the goggles and it should mirror the screen from the tablet or phone I have connected to the drone controller??