While the intended end state is that this planet can support space-faring lifeforms, the solution under question needs a sanity check. I cannot commit to many numbers with how speculative this all is at present.
The planet is similar to Pluto, in that it is small, cold, has a rocky core surrounded in ice with a possible liquid water mantle, and at least one comparatively large moon (and possibly a few other small ones). I'd rather at least one of these moons be more mineral-rich than Charon appears to be compared to Pluto, but that isn't likely to be relevant for now.
The handwavium meteorite has some exotic properties, the most significant of which is its connection to a solar system-sized pocket universe, which contains a single star. The connection allows light to pass through, but under normal conditions, that's about it. (It might allow some gravity through, if it screwing with the gravity and baricenter of the system helps rather than hurts.) It's normally one-way, and the conditions under which this could change are highly unlikely to arise without intelligent intervention, so it's effectively a large rock that emits light.
I imagine this meteorite (or maybe small asteroid-sized, if necessary) hitting the planet at a high northern latitude, and making its way south and whichever of east/west has the best long-term effects as it penetrates the surface. Then what? My best guess is that it eventually sinks to the core-mantle boundary, as the energy it puts out should melt everything else in its path, and it should bore some way into the outer core, from a mix of shere heat and the perpetual explosion wrapped in a powerful convection current it generates. I could see it having enough influence to prevent the planet and major moon from mutually tidally locking, which would hopefully allow the tidal pressures on the mantle to create periodic variation in the shape of the currents surrounding the crater.
Have I missed anything that dramatically alters the situation? What would be the most likely consequences of such an object penetrating such a planet? Is there a luminocity where the results can be more like this primordial storm, rather than a worthless hotspot or a planet-breaker?