As an urban solo shooter there are times when it's best for me to use public transportation (usually subway).
This means I need to hand carry camera, tripod, audio, lights and stands.
Camera goes into backpack (audio can fit as well).
Tripod in tripod bag.
Need to keep weight and size down to carry any lights.
Key is the whole thing, Camera, Audio,Tripod, Light, light stands MUST be hand carried up and down subway steps (even small carts are not practical)
These kinds of shoots tend to be in small locations (small office/room) so big softbox setups aren't really viable.

I've used Dracast Silkray as soft key since there's no need for softbox, making it a fast setup.
https://www.bhphotovideo.com/explora/photography/news/dracast-brings-out-super-soft-silkray-series-led-panels/BI/2855/KBID/3801
Obviously there are other similar "flapjack" style lights.
It's not the lightest of lights though.

I've thought of flex panels such as those by
FalconEyes
https://www.falconeyes.eu
Menik
https://amazon.com/Menik-Flexible-HoneyComb-3200-5600K-Photography/dp/B07JGWGQVV/din02c-20

Concern is the weight of the controller and time it takes to setup delusion and possibly grid. Possible need for heavy V-Lock battery. Making the whole thing much heavier and bulkier than the flex panel itself.

There's Kamarar
https://kamerar.com/collections/brightcast/products/brightcast-td-256-with-ac-adapter
and Dracast/Draco Yoga
https://dracobroadcast.com/brands/dracast/panel/yoga-series/
but I'm concerned by the heavy controller and, in these cases, the lack of modifiers such as diffusion and grid.

Sometimes I want a hair light.
I have a Sola ENG as well as Aputure Mini20D for that. Both have awkward aspects to their setup so I am thinking of Boltzen 30 or 55 (easy to use NPF battery built in and very small modifiers if needed).

There may be other options I'm overlooking so I'd love to hear from others about this.

I guess I'm the only one on the board that uses public transportation.

I routinely fly with two Aputure Tri-8 units.

The Aputure 672 is a bi-color panel that can be fitted with D-Fuse pop-up softbox, and accepts the Sony NP-F batteries. Not the punchiest of lights, but very light and versatile, owing to it's all-plastic construction.

+1 Gary. The Tri 8s are durable, and well built. If I was on a subway everyday beating up heads it would be my Tri 8s. They may not be the lightest solution for you but there going to work when you get there.

You mentioned the Mini 20D. I have the Mini 20c fly kit. The bi colors are not bright enough to be practical for a main kit. I use mine for accent lights and thats about it. There is other things I don't like about them. The Tri 8s are different, much better built. Sometimes there is no substitute for weight and horsepower.

Steve

I have both the Aperture 672 and Tri8. Yes the 672 is a bit fragile and while the Tri8 is built like a tank it seems to weigh almost as much. I do have the D-Fuse softbox for them which is easy to fold up and bring along. I can take either (or both) in a car or a cab but for subway. The Tri8 can certainly handle rough travel

I'm thinking about lighter still but durable. That's why I'm mulling flex solutions.

I'm thinking about lighter still but durable.

To me, that's like asking for an 18-200 1.4 that's less than a foot long and weights 3lbs. At some point, the laws of physics will step in.

To me, that's like asking for an 18-200 1.4 that's less than a foot long and weights 3lbs. At some point, the laws of physics will step in.
... but if you're shooting micro four thirds....

Flex style lights defy the law of physics. ;-)
Of course some of the less expensive ones have very poor build quality.
There's also some diversity in the bulk of the extenral controllers and power supplies.
Also some of the COB style lights are getting quite small. Again, build quality could be of a concern.