(if you know of any manufacturer that create ^14 electric kilns, please share the information with me)
"Differences between various kinds of porcelain."
That is very possible, especially with frits, a factory produced flux that is expensive, but readily available. The problem is that silica and kaolin are both highly refractory, unwilling to melt at such a low temperature. Therefor the heating process must be even, going up gradually, allowing for an even spread of heat and even conversion of silica throughout the mass.
Neglecting this process will lead to a surplus of free quartz that will weaken the final ceramics, in this case porcelain. A balance between time and heat, which is possible to manage in a longer cycle of a high firing process, will be more challenging in low firing, which is normally shorter. Therefor an atmosphere of a slow enough firing cycle is needed to allow for and even mingling and integration of silica and alumina with the fluxes at a lower temperature.
The best comparison to the process, is a cake, baked golden brown on the surface but with an unbaked interior.
A fine balance of raw materials is needed, complicating the recipe and the chances that one of these materials, may become unreliable when any changes in the mining of the raw ceramic material process takes place.
The changes that I refer to can be anything from, geological changes to changes in the processing of the raw materials.
Note that this is not traditional soft paste porcelain fluxes, however as ceramics technology evolves, chances are good that it may all blend into one low firing porcelain in future, which will, just as there are several different kinds of hard paste porcelain recipes, end up as different recipes for low firing porcelain.
It often requires down-firing. Frank and Janet Hamer described it in “The Potter’s Dictionary of Materials and Techniques” as “a thick body-glaze layer”. Due to the fact that the clay and glaze matures at the same time, it builds a very strong bond by the clay body compressing the glaze. A simple explanation is that the clay prevents the glaze from stretching too much, prevent it to craze, thus the stronger bond. Too much compression will cause shivering.
In the USA and in many other countries that I visited before, are many manufacturers, making high quality electric pottery kilns. Unless poorly designed, any of those should be suitable to fire porcelain. Higher firing, refractory materials for kiln bricks and kiln furniture may be used for cone 10 kilns, maybe allowing to last a little longer when it is used at lower temperatures than the temperature it is intended for.
Resist the urge to open the kiln when the heat is above 200 C (392 F) and even then, prevent sudden airflow into the kiln. It is not worth all the trouble and long hours, just to see how a fine piece of porcelain fall apart on the kiln shelf, or worse, weeks after you sold it to a valued customer.