Documentation about how the TMPRO shaders work

Hi,

In order to achieve UI always on top (in LWRP) we created a specialized shader, but then we realised that unity must do some trickery we are not aware of, to sort the UI elements.

Eventually we found out that the Distance Field Overlay may do the trick, however we are not confident about it and the lack of confidence is obviously due to the fact that we ignore how the underlying system works.

Is there a documentation somewhere that explains all the tricks and gives all the tips?