IMO...it IS our role as Consultant Arborists to highlight the ecological values of trees as much as their amenity value and everything else.
These sorts of relic trees are seldom seen in urban areas....and if they have extra-ordinary spatial demands (which they usually do) then we must provide that information for the CORRECT decisions to be made about their fate.
Always remember who the reader is....and that they are not tree specialists....that is why you are commissioned to as Consultant Arborist Report...Other Consultants do not always not look outside their own square unless.... it is put right in front of them.
I've had occasions, in discussing tree issues where the other party has not even visited the site.
TRUE.
You've done an excellent job on the Conclusions.
The answer IMO (& based on the info provided)
... desirable to interim retain for fauna habitat with an exclusion zone
... if possible....address relocating turn-around area
... explore althernative low-impact surfacing types (coarse gravel/ bitumen /bridged system)
... define the extent of expected tree-care obligations (scope of pruning,.re-inspection time-frames, treatment and maintenance of under-canopy area).
As long as you have provided the parameters in the report, which this tree would require to continue viability ... and advised the expected outcomes where this is not done.... then you could be confident that all tree issues were addressed.. and all decision-making information is provided.