I've been experimenting with ARAY and BRAY and I've discovered that white BRAY and tunneling BRAY (BRAY spawned by INST-sparked ARAY) don't actually spark anything; I tested this by manually drawing BRAY next to METL.  Instead it's ARAY doing the sparking; here I'll explain the mechanics of ARAY and BRAY that I've determined based on my discoveries, though most of you may already know all this and some of this is even mentioned in the tpt wiki:

ARAY, when sparked by anything but PSCN, calculates the distance to the first element in line with it that isn't one of the elements mentioned within the following brackets [ARAY, FILT, STOR, WIFI, INWR, activated SWCH, and solid BRAY], spawns white or tunneling BRAY with a life of 30 accordingly, and sparks most conductive elements.  BRAY also doesn't actually pass through anything; ARAY simply continues to spawn more BRAY one the other side of an element if that element is one of the 7 elements listed within the above brackets and stops spawning BRAY otherwise.  It also makes any full STOR in it's path release it's load, sets the life of any FILT in it's path to 4, converts any other white or tunneling BRAY in it's path to solid BRAY, and rejuvinates any solid BRAY in it's path.  In the case of being sparked by INST, ARAY not only sparks most conductive elements, but also, with the exception of INST, uses the aformentioned "passing" mechanic in response to them; in fact, tunneling BRAY and white BRAY are essentially the same thing, I just use the term "tunneling BRAY" to distinguish BRAY spawned by INST-sparked ARAY from BRAY spawned by any other means.  In the case of being sparked by PSCN, ARAY fires a line of Brown BRAY with a life of 2 and converts any type of BRAY in it's path to Brown BRAY with a life of 1; even other Brown BRAY.  It also makes any full STOR in it's path erase it's load.  But even with all this happening, BRAY is not just for graphical effect; it does exhibit some functionality.  Some elements check for BRAY, like how ARAY checks for BRAY in it's path and how SWCH checks for Brown BRAY on it's sides and turns on or off if a horizontal side and a vertical side are both occupied by Brown BRAY; this doesn't work if any element (even Brown BRAY) is occupying either of it's top corners.

In short, ARAY is doing all the work in almost every case, with SWCH doing up to half the work in particular cases.  The only thing BRAY can do on it's own is conduct heat.

NOTE:

Sorry, I put this in Creations by mistake; it was supposed to go in General.