I am, in general, a defender of the 5th editiion parma rules for my game and have not yet run into in-play problems with the pink dot problem (perhaps my fellow players are insufficiently ruthless). As such, I have not closely followed all of the parma alternatives threads.
Yet I think that I've got a take that might make others happy.
A few weeks ago on this board someone suggested a take on parma that I thought was workable and eliminated the pink dot "problem" (I can't find the post and I susspoect that they didn't even know that they did it). Here is my attempt to describe it;
Parma works exactly as presented in the book with a single exception;
A mundane object that has not been magically altered in shape or substance (but could be altered in some other way such as appearance, temperature, creo vim magic stink, etcetera) and that is not moved by any magical force will not be kept away from the caster by parma magica. Instead the parma will deform elastically around the object. Thus the parma still exists between the object and the magus and effects like the object being exceedingly hot, weeping poison, or growing spikey bits would be resisted.
A mutoed poison could not be drank.
A mundane arrow that is first shot into the target and then changed into a biting cobra would be resisted.
Edge of the sword/ spoon arguably change the shape of their target so they would be resisted. In other words a pink dot style defense could still be created, but it would need to change the shape or substance of the target. Thus it would be more difficult to do and it would need arts specific to the attacking object.
A sword that has a muto imagonemed pink dot ,is creo ignemed to be above room temperature, and has a creo vim magical air to it would not be resisted, but the heat given off by the above room temperature blade would not affect the magus unless it penetrated the magus' parma.