You should be able to have 8 players (including the host) on your home network. At least that's how it worked in older versions. I haven't tried it in a while; typically it's just me and my son playing.
What happens if the host tries this command?
/setmaxplayers 8
Of course, the host would have to drop out of survival mode to do that. Try it on a test world.
As of Bedrock Edition 1.17, lightning rods no longer redirect lightning bolts, neither when summoned by a Channeling trident, nor when summoned by a command. The lightning bolt hits the target, regardless of the distance to the lightning rod (which normally redirects lightning bolts within a 64 block radius, according to my tests).
Why should hardness and blast resistance be the same, or even proportional? Otherwise there isn't any need for two separate attributes. Blast resistance could simply be tied to hardness.
It makes sense that something hard and brittle would have less blast resistance than something just as hard and tough (not brittle).
In the real world, hardness is resistance to deformation, and brittleness is how easily something fractures when subjected to deformation forces. Blast resistance is simply how well something can absorb energy. Usually energy is absorbed by deformation or dissipated by breaking into small pieces after sufficient deformation.
Real world example: On the Moh's hardness scale, glass and quartz are harder than iron, but glass and quartz are more brittle than iron. Iron, therefore, would resist blasts better, by deforming plastically to absorb energy.
Minecraft has its own hardness scale that doesn't really mirror real world properties. However, it makes perfect sense to me that cobblestone (a rather soft stone) would have a high blast resistance. I would say, the softer the substance, the higher its blast resistance should be.