On Tuesday, April 23, 2019 at 6:11:25 AM UTC-7, wrote:
A. The only Duo on our field sold recently so I don’t have access to one for testing.

B. If you watch both videos it can be readily observed that the steep approach is discontinued well before reaching ground effect. Both flights crossed the airport threshold at a nominal airspeed. One must scrub altitude early enough to get back to a stable approach before touchdown.

Having previously owned a Duo T (pre-XL) I’m pretty confident that this technique will be similarly effective, but don’t have the means to make that video at this time.

An over-shoot landing accident isn't about fine-tuning technique: the pilot has simply become a passenger and has stopped flying the glider. The question is: why does someone who has passed the necessary demonstration of proficiency all of a suddenly enters into an out-of-body state of mind? I don't know and I don't know how to predict it.

Tom