I think the red miles early on is very much a huge, indiscriminate AoE. The way Droog uses it in act 6 to specifically target Dirk seems like a bit of a retcon of its function. Like, I know Sburb is a game with arbitrary rules and all, but using the miles to GPS track any given player smells like BS.

Jack does a lot of damage to Prospit with nothing but the miles, but its not like he destroys the whole planet as he does later in the troll session. There's no reason for him not to, when his entire motivation is wanton death and destruction. In fact, he has to cut the chain apart just to completely the destroy the moon.

And yeah, when he does destroy Prospit and Derse in the troll session, he uses the green version, which strongly suggests the first guardian prototype is necessary to like, destroy a whole planet.

Billious Slick is a whole other topic. I mean, technically Jack is only killing one living creature when he uses the red miles here, and his ability to destroy an entire universe using nothing but the red miles probably has more to do with the timespace shenanigans involved with Jack being outside of the universe microcosm than it does the strength of the red miles in and of themselves.