So, instead of testing out if heat is really spreading through the abyssalite, you just dug out all of the biomes except for the lava way at the bottom covered by abyssalite, then complain that in thermal overview it seems like heat is spreading from the magma through the abyssalite, while it could be any number of things. Ie. Hot material that you dug out, or the abyssalite itself, or the hot residual gas and so on, and so forth. Yeah.
And you personally experienced all of those things recently, yes? No way you read about it somewhere on the forums and are now using it as the entire basis for your complaint. That would be ludacris, right? RIGHT?