Sorry for the title.
While playing, I've thought of a few small things that'd really go a long way toward furthering immersion with the way you interact with the world. Some of these things have been suggested before, but I feel they're really good and go along with the theme here.

1. Grab the rope (or the pole) to change zones. The rope that is tied to the posts which lead you through the fog. I presume explorers use this rope so that they don't get lost while it's too thick to see anything. So I think it'd be a really nice touch if the player could interact with it to really drive that function home.

2. Always raise hands to open the UNPSC gate. I'm sure people will hate this one, so maybe it could just be an option in the settings. But I think it's weird that they only ask you to do it once and every time thereafter you can just sprint in like you've got a bomb strapped to your chest. I raise my hands anyway bc I think it's cool. But the gate opens a little ways before I make it to the circle so it feels a little silly.

3. Always use watch to unlock room. Similar to the prior suggestion, I think this would need to be a toggle in settings because there are fires and gotta go fast. But this is another thing I always do. It's just a really cool feature for it to only be used once.

4. Toggle for red laser selector. I like to click on the screen buttons using my finger instead of the laser. But the laser is also very distracting and often my hand will start wigging out because it isn't sure if I'm trying to interact with the screen or use the laser pointer. I'd really like to just turn that off completely. I don't think I ever actually need it.

5. Place cigarette from pack directly into mouth. Not only would this be more immersive, but it'd make the cigarette retrieval be less juggling with the backpack. It took a youtube video for me to understand smoking. I tried doing it this way the very first time, then I assumed I had to hold the cigarette. Then I assumed I was meant to hold it up to my mouth like food. Then I couldn't figure out why I wasn't inhaling and gave up until I saw someone doing it on a clip.

6. Open energy drink like the cans. Make it crack and fizz. Such cool. Many immersion. Very wow.