Might I suggest basically having two types of meteorites, one that dynamically scales and one’s that don’t scale. Basically being differentiated by the color they glow or are.
Dynamically scaling ones would have a higher chance of spawning on moon and ring worlds, where players seek more challenging content, also increasing usage of the feature of warping to friends. Or just simply warping in the boundless planets with players in the area.
While non scaling ones would be more frequent on starter planets, where players are just looking to learn the ropes. And so they’re looking for help to clear the meteors but not necessarily looking for it to be made harsher with the more people there is.
For the matter of scaling, it might have to deal with a timer. And it scales for a certain amount of time. Say first 5 minutes it will break down or spawn more little meteorites depending if the people joining the fight decreases or augments around a certain radius around the meteor.