Shendrones Smol Baby
Smol Baby is a 106mm 2" X8 with a 2.5mm baseplate and a 1.5mm bottom plate. It's built upside down so the main body functions as its landing gear. There are 8 1mm motor mounts, and you only use 2 screws per motor with the screw heads nestled in the baseplate. Motor mounting pattern is 9x9 M2.
There are mounting holes for 16x16 as well as 20x20 stacks.
Carbon and hardware is 27g, the build pictured is 144g.
I'm calling this one a beta 'cause I'm not super familiar with small components so you'll have to improvise how you mount your components.
Smol can carry a full Hero on 3 or 4s, though optimal performance will be with a decased Hero.