Hi Keith,
I had not assumed that we were operating at FLLTOM, as there were no indications that we were. VMCG is unlikely to be limiting (assuming a well designed aircraft) at anything other than very light weights. I suppose you could arrive at a very light FLLTOM by operating from a very short runway, in which case you would have to look for more headwind or at least turn the packs on.
I think we might be working from different editions of CAP 698, my version (July 2006
http://www.caa.co.uk/docs/33/CAP698.pdf) has the following instructions:
2.5.2 The Calculation of V Speeds
To calculate the V speeds use the tables (at Figure 4.8 or 4.9 as appropriate) in the following manner:
a) Enter the density sub-graph (below) with pressure altitude and ambient
temperature to determine which of the columns of the tables should be used.
b) Select the tables appropriate to the flap setting from Figure 4.8 or 4.9.
c) Enter the V speed tables at the actual take-off mass. Extract V1, VR and V2.
d) If it is necessary to correct V1 for slope and/or wind component, enter the table at the top of Figure 4.8 or 4.9, as appropriate, at the actual take-off mass and interpolate the correction necessary.
e) Apply the corrections to V1.
f) Use the sub-table below Figure 4.8 or 4.9, as appropriate, to determine the VMCG. Enter the left column at the ambient temperature and then proceed right along the row to the appropriate aerodrome pressure altitude (interpolating if necessary). Extract VMCG.
g) Compare V1 with VMCG. If V1 is less than VMCG, take-off is not permitted.
h) Check TORA exceeds TORR. If it does not, the take-off mass must be reduced.
and instruction (g), rather than your (vii) is significantly different.
Springbok may correct me but I'm interpreting his statement as 'I'm not FLL limited and I can't operate at this silly light weight because of VMCG so I'm going to have to tanker some fuel to increase the TOM and get a higher V1'.
There are, of course, other techniques available if you're not FLL limited such as choosing a higher V1 if a range of speeds is available. I don't think that the CAP offers this as an option. This is probably in keeping with modern operations, I certainly wouldn't like to do a range of V1s calculation on a 20 minute turn around.
I get your point about the 'assumed higher weight'. It would certainly work.