Adding my two cents here... those batteries really do disappear fast lol. I've been super happy sticking with the official Sony NP-FW50 Lithium-Ion Rechargeable Battery because I'm always paranoid about third-party ones failing when I'm actually out in the wild. I've had zero complaints with the OEM ones and they've lasted me years without losing much capacity. Peace of mind is worth the extra few bucks when you're miles from a charger. Since you're doing the Smokies, honestly forget the neck strap if you're hiking. I switched to the Peak Design Capture Camera Clip V3 and it totally changed my experience. It clips the camera right to your backpack strap. It feels way more secure than having it bounce against your chest all day, and I've never felt like it was gonna fall off even on steeper scrambles. Much safer for the gear than a swinging strap imo. Also, dont sleep on a good blower. I always keep a Giottos Rocket Air Blaster Large in my bag. Since mirrorless sensors are so exposed, you're gonna get dust on it eventually, especially if it's windy in the mountains. It's such a simple thing but it keeps the sensor clean without you having to touch it and risk a scratch. For the grip issue, a cage is cool but it adds a lot of weight for a long hike. Maybe just see how the handgrip feels after a day of shooting before you commit to the extra bulk. Have a killer trip!

> Is a screen protector actually necessary or am I overthinking? You definitely want a screen protector. One scratch on that LCD and the resale value drops instantly. I would suggest getting something like the PCTC Tempered Glass Screen Protector for Sony a6400 since they come in multi-packs for cheap. Its basically cheap insurance. As for the cage, be careful because they add significant weight. If youre just worried about the grip, a SmallRig L-Bracket for Sony A6400 is a more cost-effective way to get more surface area for your pinky without the bulk. Spare batteries are non-negotiable tho. The NP-FW50 cells are tiny, so I would grab the Wasabi Power Battery 2-Pack and Charger for Sony NP-FW50. Third-party batteries save you a ton of cash without sacrificing much performance. For the strap, the Peak Design Slide Lite Camera Strap Black is the standard for mirrorless setups and much more comfortable for hiking in the Smokies.