Whenever I encounter the biome shattered glacier, a ton of ice suddenly starts melting. I'm not sure if it's the black ice or packed black ice, if the latter even spawns naturally. This is with Tectonic, so the normal biome temperature distribution might be a little off. I suspect this would be a compatibility issue with other terrain gen mods as well. If modifying the biome temperature doesn't fix the issue, perhaps make it so black ice doesn't melt, or make that a config option? It's really weird to approach an icy black mountain and then see it turn to water and everything starts lagging.

The same thing happens with the Eroded Borealis, covering the spikes in a layer of water

So Most likely something is messing with the temperature, we use the vanilla ice code so we can't make it configurable best option would be to report to tectonic that it's messing with biome temps