It's not a solution to a problem. A tied VP count can be just as rare or as common as your VC allow it to be. It would be trivial to come up with a VC where VP ties are very common. Didn't you write a scenario design handbook? I would have thought you would already have thought of six or eight possible ways to do so.
My deep and extensive knowledge of the subject is exactly why I see no practical purpose to what you're suggesting.
I have invented a game feature.
As stated above, I'm reasonably sure others have considered this. You have the advantage in that my time is too valuable to be searching the 5,000+ extant scenarios to find an example. Other games certainly have already done this - Combat Mission comes to mind, with its variable time endings, though they are not triggered specifically by tie VP counts.
I can see a clear rationale for a variable time limit in ASL scenarios, not tied to the requirement that the VP totals are identical - and these are already fairly common in the game.
There is no need for a rationale for it.
No need to seriously consider it then, either, one can conclude.
Is there a rationale that the NFL had no overtime during the regular season before they adopted it in 1974?
Are you kidding? Pro sports leagues have entire rules committees that draft, trial, assess, and implement rules changes. They also communicate the changes to the public, and explain the rationale for the rules changes.
https://operations.nfl.com/football-ops/league-governance/the-nfl-competition-committee/
Here is the official web page of the NFL's competition committee. "
The NFL’s process for modifying or adopting rules and regulations
is systematic and consensus-oriented. The Competition Committee reviews all competitive aspects of the game, including (but not limited to)
playing rules, roster regulations, technology, game-day operations and player protection."