I'm surprised to hear that you think mirroring a symbol and changing one property is 'very time consuming' and, of course, you only have to do that once. When it's done; you can just copy and paste (or save the result as a new custom symbol that you can use in any drawing).
It's a fair point that bi-directional ports break any uni-directional standard - c'est la vie! - and, of course, a port has to go on one side of a symbol or another, and sometimes the port will be on the wrong side, but this depends on the particular system.
We think it's ok to 'turn' a cable, or a symbol, or a port (there is a movie on this at https://www1.stardraw.com/stardraw2/sd7/movies
) wherever it's necessary, but I understand why you might employ a personal standard that does not allow this, and we want to allow flexibility where required.
So, I'm happy to say that there is now a folder of Reversed feathers, under Stardraw Online Symbols | Feathers which, in this case, seems appropriate as a solution.