Just anecdotal but below 3000k gets odd for me in real use. I loved my 2700k Samsung lh351 TIL I got in a cave with it. Something about the color temp made the walls more difficult to navigate.
Warm tints are comforting at home but I would experiment before I put a lot of stock in them.
At home is where I plan to use mine. I’d think that 4000k would be nice for caving but I base this on a gut feeling and NO experience in caves.
Application is everything. Yeah, the old carbide lamps were probably more neutral than 2700k. Oil lamps? Maybe that or lower. For caving I’d go with 3500~4500k.
I have one 3000k emitter, an older 219B in my TH20. The driver doesn’t push it so it’s a bit of a weak output. But terrific for hands-free illumination of close range tasks. When going outside at night to push trash & recyclables to the curb, it’s an ideal choice.
With dark adapted eyes I find absolutely zero need to exceed 4800-5000K cct. I also agree that dipping below 3300K really starts losing visibility fast for active tasks. My pattern these days is CW/low CRI is strictly for throwers (Osrams mostly), my EDC is between 3900 and 4500 (favorite is 3500+4500 mix e17a) but typically is SST20 4K. I find a 2700+4000 sst20 mix a great house light mix. I have a 3000K sst20 in a p60 that I keep around just because, though it’s never used. But a light that gets used every night is my beloved 2000k e17a quad H03.
What do you mean by “more neutral”? Carbide lamps run at near 2200K. Oil lamps cover a fairly broad range of CCT from 1900K flat wick lamps to 2700K incandescent mantle lights.