Heat transfer through abyssalite (water only)

I don't think this is a bug, this happens to oil in the oil biome pre-alpha. The oil will flash into sour gas and petrol, while decreasing the temperature of the abyssalite until it was no longer high enough to flash the crude oil any further into natural gas and petrol. I'm guessing that your abyssalite also dropped in temperature until it was somewhere just below 100C?

The behavior isn't new. But the map generation regarding it is a lot worse in the expansion. In the main game the upper layer is not uniformly hot. There a few hot spots, which can be managed. In the expansion the upper tiles of the barrier seem to be hot basically everywhere, which causes a lot of issues.

The following screenshots were taken on various planets with seed SWMP-C-981086416-0

 

Here we have to water pockets in a swamp biome immediately boiling. This should not be happening. It causes a lot more issues than oil boiling

 

This is probably caused by the smaller map size. Two total breaks in the barrier caused by the oil reservoirs spawning and cutting the magma biome apart:

 

To the left you have the usual petroleum boiling. As said that happens in the main game too. On the right there is a blob of magma on the wrong side.

 

Magma pools like that aren't uncommon. This is on the main asteroid. Three hotspots. The magma melted the rock and cooled down that way, but the heat has clearly radiated out

I don't think this is water only, as I had a Iron metal tile (refined Iron, not ore) adjacent to a ~1000°C Abyssalite tile. The Iron tile started heat up as soon as I saw it.