There are occasions where a remote release can be very useful, especially if you need to get close to your subject and haven't got the lens to do it. What I like about the Canon Connect is that unlike normal remotes that just take a photo you can actually change settings as you view. It's worked well when I tested it on the 5DMk4 .I don't think the cards are the problem as the last time mine locked up I was only focussing on the bird and hadn't taken any shots for a while. I'm using a single SD card and shooting short bursts with CRAW.
Canon Connect is a great app, I've used it to transfer images to my iPad. I can operate the camera with my iPhone but I prefer to have my eye up to the EVF for all shots other than low-level when I have the screen flipped out. Have to say though, problems aside, it's a phenomenal camera. I can't see myself going back to a DSLR after using mirrorless for the last 2 years. The animal eye tracking is out of this world.