I agree....
...that we should be able to do a provisional with SWORD or CIRRUS fuel, but very often the final fuel is several thousand KG's over that in the system. So, we're told (by our management) NO provisional without either ACARS or FICO fuel, or final fuel from the TRM.
(As an example, a LHR-MAN sector today increased by 4500KGS. A LHR-JFK increased by 8000KGS). My (non-CLC) LHR-SIN last night increased by 12,500KGS. )