I'm creating some custom symbols for an industrial P&ID, and I'd obviously prefer to keep the total number of symbols in the palette to a minimum. One of the symbols represents a centrifugal pump, and I'd like to represent both a vertical and horizontal outlet orientation (see attached) with a single symbol. Currently the pump housing and outlet (circle and chimney-looking thing) are a single path, the base is a single path, and the group that contains them is the content of the symbol. After dragging the pump symbol onto a canvas, is there a way for me to apply a 90 degree rotation transform to only the "pump housing" path without breaking the link to the original symbol? What if the pump symbol were actually just a linked imported svg? Just a simple clone within a document?

I would just use two symbols, unless one is rarely used; then I'd break the link.  The whole point of symbols is grab-and-go for frequently used objects. Keeping symbol count to a minimum is not a goal in itself... if you're gonna use them, they should be there, otherwise not.

Thanks for the quick response @TylerDurden. Yeah I'm realizing I had some misconceptions about symbols. But in any case, I still have the same question about clones, so I rephrased it and posted it as its own topic. 

Symbols and clones are the same thing. In both cases they're implemented as SVG <use> elements, so have the same limitations. In short, the SVG code looks something like this:

ORIGINAL:

<g id="thing">

...lots of individual elements

</g>

CLONE:

<use xlink:href="#thing" />

As you can see the clone is literally a single <use> element that holds a reference to the parent. There's nothing inside it, so no way to change just one element within the cloned copy.

I concur with TD's statement that keeping symbol (or clone) count to a minimum is not a goal in itself. They're useful for some purposes, but when they stop being useful, break the link and work with real objects.