I gave up the quest for BBS at the beginning of 2020 and have not looked back.I know it will sound crazy but I am almost relieved to hear that the Blackbird is going to be hard to match as far as closeness goes. Not just with the Sabre or Vector but pretty much any razor.
It has honestly taken the pressure of me to try to make every razor match the shave and closeness of the Blackbird. The last 3-4 shaves have just been about enjoying the shaving experience not matter what razor I am using. As someone who just got into this as a hobby, it has been a real good learning experience.