Using your depiction and Klas' reasoning, neither the LOS/LOF noted in yellow nor those in green would be able to receive the FFMO if the 628 were sing road movement in X7 because the LOS/LOF is not traced entirely through road hexes and the target hex is a wood/road hex (the hex still being a woods hex).
Not sure I'm following you. I labelled X7 as a PFZ vineyard in the diagram. It is no longer a woods-road hex, but a vineyard-road hex. However,
if X7 were still a woods-road hex, I believe that fire traced from the Y6-Z5-Z6 vertex would qualify for FFMO (although fire traced from Z7 would not).
It is for that reason I feel a unit utilizing road bonus fired at from a higher elevation as in the OP situation would receive a FFMO modifier as the type of hex it is moving through is immaterial. There is no hindrance the fire is traced through on the way to the target making the target in OG (to the firer) as per B3.3 and B3.43 indicates the presence of Brush in the hex is not a road negating circumstance based upon the LOS/LOF as the unit is not using the Brush in its movement. YMMV. (Would be an interesting Q&A).
To be clear, as I mentioned earlier in the thread, the unit in the OP's diagram would be subject to FFMO, because the target satisfies the
second condition of A4.132, the condition that does not require a clear LOS be traced to the hex centre dot.
As for treating the target as in Open Ground to fire traced from a higher elevation to the centre dot, we are in uncharted territory because brush-road hexes (not to mention grain- and vineyard-road hexes) did not exist when the B3.3 was written.
I think I get what you are driving at regarding B3.3 and B3.43, namely that an Infantry unit using the road movement rate is considered to be in Open Ground regardless of what other terrain exists in the hex. However, I believe that this Open-Ground status is conditional.
With only A4.132 to go by, I'd suggest that the brush depictions
within the target hex may still be enough to prevent the application of FFMO. It is clear, for example, that any
same-level LOS drawn to the centre dot must clear any in-hex brush depictions in order to qualify for FFMO. Beyond that we can only speculate how A4.132 might be applied in cases where the firer is at a higher elevation. Maybe, a firer also needs to be adjacent, not unlike B9.33, to qualify for the FFMO DRM. (Bear in mind that the road depictions are abstractions, and that the width of roads tend to vary, especially dirt roads.) Interesting discussion, and worthy of a Q&A due to the novel situations created by the "Fort" boards.
However, you got me thinking of another related point.
Imagine a unit at level one in PrBV26. Based on a strict reading of A4.132, a MMC entering S24 (from R24) using the road movement rate may not qualify for FFMO based on the first (centre-dot) condition. However, FFMO still ought to apply because the MMC would satisfy the second condition wherein a clear LOS could be traced to the road depiction of the R24-S24 hexside. Moreover, LOS drawn from level one in V26 ought to satisfy
both conditions of A4.132 when targeting the MMC as it enters Q23 and R24. Regrettably, Primasole Bridge sidesteps the issue by having no level-one Locations.
Hex Q23 is an example of a brush-road hex. Footnote R on the Chapter B Terrain Chart applies to all entrance costs, and
A4.132 applies unchanged.