uhm... dude. You think rotation is a problem? Are you saying that if I hand you a pamphlet written in English upside-down it's indecipherable?
First up, remember always give humans credit for their ability to interpret language in context. If someone's reading a newspaper, they instantly recognise when it's upside-down, sideways or reversed. Likewise, when you know Sarus well enough, it only takes a few words to identify whether there's a problem. For example if you start reading Sarus from a piece of paper (assuming there's no other markings on the page to indicate which way is up, like page numbers, date, headings, illustrations), you would know after a few words whether it makes any sense.
Unless you're reading from a circle of paper with no up, down or sides, this isn't some kind of frustrating dilemma. After reading something like "f lmf mm dls tdm mss" you'd only read three words and realise it makes no sense.
Secondly, remember that septaglyphs are drawn at angles of 51˝° from each other. This means that D is the only syllable that points directly up. Rotate a rectangular page of Sarus by 90° and none of the septaglyphs have a syllable that points directly up. Rotate it another 90° and still, nothing pointing up. The beauty of 7, you see
Now, if I were to write something in the sand (or on any other surface with no obvious direction) then yes, I would put an "up" indicator on the glyph, but rotation isn't a disadvantage, it's a quirk of the language. Seriously, how efficient that you learn a septaglyph, then simply rotate it for 7 different meanings! I love that aspect.
btw, I mentioned encoding Sarus with rotation a few years back. Probably back on the old forum or perhaps in some early B525 lessons.