PIPE and PPIP can be tricky when you need 2 different lines the transport two different things, because you can't cross the lines.  These new elements fix that:

Smart pipe (or SMRP):

SMRP functions much like PIPE, except that if 2 1px-thick lines of it are drawn in a plus formation the center particle won't transfer contents to a different y coord if it recieved them from a different x coord and vice versa; the particles touching the sides of the center particle also won't transfer contents diagonally.  This is similar to how INST doesn't conduct diagonally in a plus formation.  This ability to cross lines is only viable with lines of SMRP 1px thick.  Unlike PIPE, it doesn't check for STOR; instead STOR checks for it.  This means that if STOR with a ctype is stacked on top of STOR with a different ctype, both pixels of STOR will pass the element that matches their respective ctype to SMRP and since particles can be stacked up to 5 pixels, up to 5 different elements can be passed to the same line of SMRP with STOR propped up against the entrance.

Powered smart pipe (or PSMP):

PSMP is the powered variant of SMRP (see above).  It responds to PSCN, NSCN, and INST the same way PPIP does and like PPIP, it's immune to pressure.

EDIT:  I modified the crossing mecanics to be more feasible.

I tried using that script; but as cool as SPPC is, it's still only possible to cross the lines in a plus formation with a 2x2 square in the center.  What's the point of "bridge" SPPC if you can't make a "plus crossing"?  These suggested elements would make the "plus crossing" possible.  There's also the new mechanic with STOR suggested above that would allow more than one specific element to pass to PIPE or PPIP.  I guess you could prop up to 3 pixels of STOR to entrance and filter up to 3 elements, but SMRP and PSMP taking elements from "stacked underneath" STOR would make multi-filtering more compact and allow the filtering of up to 5 elements.