Wrt Ringworld, I did say that the celestial ramifications were interesting, not simple. It requires a Realist rather than Mythicist analysis, and relies upon the idea that Glorantha has suffered many impacts both from outside the Ring (eg the Crater, Kero Fin) and from inside its plane (eg Magasta's Whirlpool). The Darkness is the result of secondary impacts triggering forest fires across the local arc etc.
As so often with Glorantha the mental reward is not from the initial theory but rather from calculating possible outcomes and then seeing how it integrates with the wider mythology. đ¤