Well, I have been playing with the steam output reactors for a while, and I see that it's not really that HAYO-ish. I have an idea to make it better, so if you can spare a few minutes, please continue reading.
Basically, the idea states that, when steam-outputting reactors are enabled in the config file, the inventory space of the reactor is reduced to a 1x6 grid, increasing by another 1x6 column for every adjacent chamber, with the grid shoved to the far left side of the GUI. Here, only uranium cells can be placed, no other components work. (maybe even disabling crafting of other components when the config option is enabled...). In the remaining space, there are two liquid-bars, one for steam and one for water. Here's a rough example of a complete reactor's GUI:
The 7x6 grid is for the single/dual/quad Uranium cells. In the upper-right corner, there are two liquid bars. The left one holds water, the right one holds steam. The little bar under the left one shows the steam production (how hot the water is, not the hull - starts at 0, reactor starts making some steam at 25%, and steam production rises from there). And the little ''Hull heat'' text kinda describes itself - all it does is read the reactor's hull temperature and output the value, in percent, where 0% = 0 and 100% = meltdown.
Basically, As long as there is water in the reactor, it heats water into steam rather than dispersing the heat to the reactor hull. But, if there is no more water to heat into steam, the heat is dispersed into the hull. Also, if the reactor is shut down when heat is in the hull, the heat will be used to boil water into steam, until it either runs out of heat, or runs out of water.
At 25% steam production, 8 heat = 1 steam, 50% is 4 heat = 1 steam, 75% is 2 heat = 1 steam, and 100% is 1 heat = 1 steam.
Also, it may be somehow possible to make a bigger GUI (I have seen it in other mods), allowing more room for the water/steam bars, and steam production bar.
If you like the idea, or have an idea to make the idea better, please leave a reply. Thank you for reading.