OP, don’t mean to cause you additional worry, but have you confirmed with B&W that replacement tweeters DO NOT have to be matched in order to meet their design goal? Does B&W match the tweeters used in these speakers? Perhaps not. Some manufacturers use only matched pairs for some of their models. I went through this with speakers using Dynaudio tweeters that needed replacement. The new tweeters were simply stock replacements (not matched as were the originals) and the result was a slight but audible reduction in image stability.
Buyer Dispute
I would like to have some opinions of a remedy for this issue:
I purchased a pair of B&W 804D3 loudspeakers through Audiogon in August 2021. They were shipped in original containers by freight. The boxes arrived damaged with some holes in the boxes, but no damage to the speakers accept for one very small spot, which could be repaired with a drop of stain. However, neither tweeter was functioning. A multimeter revealed an open circuit across both voice coils. The seller said that they worked before shipping but offered to send me replacement tweeters under the previous owner' warranty which I agreed to. However, and here is the rub; Because of supply chain issues, Bowers and Wilkins did not, and still does not have the tweeters in stock. I have been waiting 6 months for the seller to provide the replacements from B&W, but they continue to be out of stock. In short, I paid nearly $7,000 in August 2021 for speakers that I still cannot listen to.
Any opinion on a path to resolution?