Does an ÜberCharge last longer if the patient is taking damage?

We know that there are a few rules about the rate you build an ÜberCharge at, such as:

• You build ÜberCharge faster if the patient isn't fully overhealed.
• You build ÜberCharge faster if the patient isn't healed by somebody else.
• You don't build ÜberCharge if you aren't healing anybody.

Do these rules also apply while you deploy an ÜberCharge? Is healing an ÜberCharged patient going to reduce the length of the ÜberCharge? If the patient isn't taking damage, does it mean the ÜberCharge will be shorter? If your patient dies, does your ÜberCharge deplete much faster?

Solution 1:

The duration of an ÜberCharge is always 8 seconds when you keep a single patient; the only thing affected by a patient's health status during an ÜberCharge is healing, which is a separate matter from ÜberCharge.

The only thing that shortens the duration of the ÜberCharge itself (for the Medic), and not the filling of the charge meter, is passing the healing beam to multiple patients such that more than one person receives invulnerability.

Solution 2:

For a condenced answer spesific to this question:

Übercharge-meter doesn't gain any charge while its being used.

For more exhaustive answer, see The Annoying Pyro's answer.