The calibre 829 project was costly, but possibly due to the ready availability of lesser chronographs at cheaper prices, the response from the market wasn't exactly hot then.
Gunter Blumlein was one of the most (if not the emost) admired industry leaders. He re-started A Lange & Sohne from ashes, turned around the near bankrupt IWC and changed Jaeger-LeCoultre from a relatively unknown high quality movements supplier to a reborn manufacturer. He is admired by most in the industry, and although some detractors referred to him as "The Master of Deception", he was much respected even by his enemies.
The late Mr. Blumlein believed that if a product is ahead of its time, it will fail.
This is my speculation, and similarly your theory about Jumping minute is also pure speculation, is it true? I don't know, one JLC executive once told me "As far as I know, Lange did their own Datograph".