Opinions on a "Vote: Timer Reset" for DF parties on the cusp of a clear?

[kyuven]

In my example, people will have the option to vote no and leave without penalty. So the "trap" groups would only continue if everyone wanted them to continue. .

You're missing the point of what the "Trap" groups are.
A trap group would constantly set the group to refill, and people would join constantly expecting to actually do the content. Even though they can leave at any time, the timer will be constantly reset so people will constantly get paired with this group, which is doing nothing.
In other words, a single person can screw with an entire data center by doing nothing but clicking a box every hour and moving his character every 5 minutes.

And this sort of thing already happens, but since they get kicked out of the instance after the time expires it's less of a problem.

And then there's the votekick problem. Let's say you're doing this wonderful group but one of your members is slacking, so you kick him. Then he rejoins. You can NEVER be rid of him. This actually happens a lot with certain less popular dungeons at non-peak hours, and would only be exacerbated by a lack of a timer.

And again: If this is the case, why not just get rid of timers?
Why bother having timers if you can just reset it?

There would still be limitation, for instance, one vote-extend per instance for .x the initial duration. Issue?

Again, then, why bother having timers?
And again, outside coil, if you're not able to beat it within the time allotted, you REALLY should take a break. The game is trying to tell you this.
Also, what about repairs? If you're going after this fight for 2 hours, you'll likely need repairs at some point. Not everyone is a crafter.

In truth, this would require a lot of effort and testing to pull off for very little return. Most parties who go into DF will either clear it in the time allotted, or not be able to clear it. The number of "Just 5 more minutes!" groups is far outweighed by the first two categories.