Would like to make a small suggestion. Is it possible have a config option that controls how quickly liquid heat sources are exhausted when they are used to heat things like the refinery? Placing down a source block of something like Blazing Pyrotheum, it's consumed in literally 6 seconds.

Just to note, although Pyrotheum is consumed super-fast, it does transfer all its heat into the refinery almost instantly, getting it to max temperature. One bucket of pyro can refine 240mB diesel and 170mB LPG (in a two-block refinery).

With a fully-insulated refinery (exposed faces covered with any non-heat-exchanging block), that jumps to around 800mB diesel, and 400 mb LPG, which is loads. So I don't see a need to improve the overall heat capacity of pyrotheum, but I would be open to making the heat transfer somewhat more slowly. All fluids have a very low thermal resistance of 10 right now, with the exception of water and lava, which have a resistance of 500 (which is why lava is a lot slower than pyro to heat up a refinery).

Related suggestion : why not adding Magma Block as a Heat source?

Yes, Magma block should be added.

Regarding heat transfer rates, I do want to look at this more closely once I've finished with Amadron. @Boolyman Are you suggesting that the block should contain more heat overall, or should simply transfer its heat more slowly (so need replacing less often) ?

I've made the thermal resistance for non-vanilla fluids configurable, via the D:fluidThermalResistance config value. Raising that will make heat flow more slowly between fluids and blocks like the refinery. Note that it affects all fluids; it can't be set on per-fluid basis. And it doesn't affect the total amount of heat in a block of pyrotheum, just how fast it transfers.

Fixed in 0.7.4

Sorry I did not check back on this sooner. But you nailed it perfectly... the rate of transfer is really all that I propose need configuration. Thanks for the quick response!