I'm conflicted as to where to credit upcoming flights to, there's a few things at play here. I'm not sure how often I'll have to fly ST (I'm BA Gold easily each year on OW) so I wouldn't work things out based on any guaranteed rate of travel. My last ST flight was nearly a decade ago.

I'm looking at either Delta (who I used last time to credit to) given no expiry, Flying Blue or Virgin Atlantic (given I have a stash of miles also). All 3 programs I can credit my AMEX miles to which I believe that takes care of any miles expiry issues? I will sign up for Bluebiz regardless, as you may as well double dip (the same as I do with BA and BA OnBusiness).

Earnings on VS appear better than DL, but there's not many reports of crediting AF code flights to VS since the announcement/change was made by VS last year.

My upcoming flights are a mix of J and Z
https://www.wheretocredit.com/air-france/j (short haul tends to book into this on my connecting trips)
https://www.wheretocredit.com/air-france/j (my mid/long haul tends to book into this on my connecting trips)

I can status match to VS and get Gold right away (possibly), but VS seems to require crediting of a VS flight to seal the deal, rather than AF/KL (which is the flights I'd be taking).

Flying Blue has the benefit of being able to double dip by also earning Accor Live Limitless rewards also.

One more to throw into the ring, Air Europa. The miles could sit there and turn into Avios...... if/when that deal closes, but that's not guaranteed and with no easy way to earn miles in the program otherwise, they could expire.

Questions

(1) What is most important to you in a FFP?
Reply: good award redemption rates
(2) How many miles do you usually fly each year & in what class? How many flights/sectors?
Reply:1-4 trips, 4 sectors per trip (2x short-haul, 2x mid/long-haul) 5-30,000 miles / year
(3) What types of fares do you usually buy ?
Reply: Business
(4) Can you choose your airlines and/or class of service? Do you travel for work and/or pleasure?
Reply: For ST it tends to be work related, there's little choice in airlines as not many service the routes I travel
(5) Which routes do you fly most often
Reply: UK to Africa
(6) What is your home airport?
Reply: LHR/LGW
(7) Do you have FFP status of any kind in an airline? What is it? Do you have any miles banked in a FFP?
Reply: BA Gold (large balance), miles held in VS (medium balance) and DL (small balance)
(8) Preferred Airlines
Reply: AF/KL/DL