I have a 2018 PHEV so maybe it isn't exactly the same but probably is. Things I have noticed:
1. The app sucks. Nor is it obvious which app you are supposed to use/download. After considerable effort to get UVO up and running it worked. UVO eco.
2. It won't remote start if the doors are unlocked or the key is in it. So if by chance I forgot to lock the vehicle I remote lock it first then do the remote start.
3. It's not really remote start but I call it that. If it is air conditioning the vehicle doesn't start...not necessary. But it needs to heat the engine up to get heat.
4. I often use the website on my laptop to do the remote start instead of the phone app. It is more reliable. So if leaving work I log into the owner uvo thing website and kick off the heat.
5. Recently Kia updated the owner website and uvo website to integrate it into a single website. Besides these remote functions, you can get full owner's manual there so just check your owner's manual. It also contains recall info.
6. If the engine starts up because I told it to heat the cabin, then a few things seem to be true.
a. The engine warms up ridiculously fast. Lots of new cars do this. There's a heat exchanger on the exhaust pipe that captures more exhaust heat and circulates coolant through there to heat up the coolant which of course is where the heat for the heater commes from. So it takes only maybe 2 or 3 minutes to start throwing heat out of the heater vents.
b. The engine will shut off once the water is sufficiently hot and the heater will run off the latent heat until the temp of the water drops to some threshold. This might be why it shuts off quickly.
c. I think it runs a max of 10 minutes either way. Maybe it's 20. It'll say in your manual.
Regarding the 'leave space'. I don't think it's necessary but yes I typically do. For example when leaving home with a full charge, I won't heat the cabin up first. I'll get in and drive it a mile with the climate off. Then I hit the auto button and the engine kicks on.
1. I think my method is likely a bit unnecessary. Most people would prefer a warm car.
2. The engine runs at I believe a constant 2000 rpm which also is another reason why the engine heats up really quickly while parked.
3. I don't think that the engine charging the batteries is as efficient as the engine directly driving the wheels, but at least as a method to warm up in stop/go traffic and while parked, it is a nice constant rpm at an efficient speed.
4. My way to work is 45 miles the first 25 of which are straight north at 70mph. The EV mode with the engine running constant 2000 rpm doesn't heat up the engine at that speed due to the fact it is taking it a great deal of cold air (often driving into the wind) so instead I put it in HEV mode and the engine drives directly and works harder and heats the engine coolant up properly. Then once that is complete and I'm about 12 miles out, I switch to BEV and the gas engine won't kick on at all.
So if you are going over about 20 miles in cold weather, I suggest just putting it in HEV mode the first few miles and heat the engine up good. In my case it doesn't hold the battery constant charge anyway even in HEV mode. It drains the battery slowly.