Shortest-proof-game challenge

Part 670091 of my quest for another undualed proof game:

#6454 diagram 1 has duals:

#6454 diagram 2 was cooked by Euclide [solving program]:

Are either undualed?

#6457

The first one has a unique solution in 17.5 per Euclide.

Second has duals.

Fresh position.

@6459

First try

#6459

17.0 moves

10.0

Is this unique?

This solution isn't. But maybe it can be shorter.

Here is one of several solutions to the 14.0 SPG, per Stelvio 2.0, solution time 11 seconds.

Here's another proof game in 14.0. No promotions.

Ah, I overlooked that; very tricky alternative route. I intended for the promotion line to be unique, and I didn’t see any other non-promotion path, until now.

Perhaps if I move wBg7 to f6 (or e5/d4) and add black’s g-pawn back, the solution will be unique? I think the bishop would interfere with the black queen this time.

@6468

I think it is unique

But what about this game, among others?

Here's a proof game in 41.5.

Here’s a proof game in 39.5. Trying to check for duals with no success yet.