The Old Parma Magica Problem - What is wrong with this solution?

[OneShot]

@Whitescar

Proposed Ruleset

• Any thing that is actively magically-controlled (Rego) will be physically blocked from reaching you, stopping or being diverted about an inch from your body. (this is standard rules in 5th ed., but thanks to YR7 for clarifying wording)
• Any spells or spell effects which target the magus, or something of which the magus is a part (e.g., a group or room) have no effect on the magus (again, standard rules).
• Any damage or damage bonus or loss of fatigue levels caused by a magical effect is reduced to zero ( Non-standard , but this is the part that seems to solve many problems)
• If something with an active magical effect comes within an inch of the magus and fails to penetrate, the magus will become aware that the entity is under an active magical effect (e.g., poison made to look like water, or a deadly snake turned into a scarf. Non-standard ).

That is indeed different from:

@Whitescar

this version of PM does not generally dispel effects. It just makes the magus aware there is an effect, and "dispels" (i.e., cancels) any magical damage or fatigue loss.

Let's look at this then: "If something with an active magical effect comes within an inch of the magus and fails to penetrate, the magus will become aware that the entity is under an active magical effect". But the Parma does not prevent that 'something' from coming close to the magus, if it does neither cause immediate damage nor fatigue loss. Right?

So, if a murderous apprentice casts a MuTe(Aq) base level 3 spell lasting only a moment (maybe even less than the customary 2 seconds), which causes the ground underneath the feet of the magus to turn to water some three meters deep. Your Parma would now no longer protect the air one inch around the magus from the magical water - because that water does neither cause fatigue nor damage, right? But when the magus has sunk into the water, the spell would expire, the water turn back to earth, sand or stone, and encase the magus without air to breath or space to move, right - killing him unless he can quickly cast under duress and without voice or gestures an escape spell.

Is that really intended? Or do you still get a long list of other things than immediately caused fatigue or damage, which the Parma shall protect against, if "an active magical effect comes within an inch of the magus"?