<InternalName>SoilEnhancement</InternalName>
<DisplayName>SoilEnhancement_Name</DisplayName>
<ShortDescription>SoilEnhancement_ShortDec</ShortDescription>
<Description>SoilEnhancement_Dec</Description>
<Icon>SoilEnhancement.png</Icon>
<BuildIcon>SoilEnhancement_Build.png</BuildIcon>
<ListIcon>SoilEnhancement_Icon.png</ListIcon>
<ImprovementType>Terraforming</ImprovementType>
<PlacementType>Terraforming</PlacementType>
<IsColonyUnique>true</IsColonyUnique>
<LandPercentageMin>0.3</LandPercentageMin>
so heres the xml data on soil enhancement or at least some of it the important line here is that last one <LandPercentageMin>0.3</LandPercentageMin>
this means that to use soil enhancement you need at least 30% of the tile to be covered in land mass and looking at your picture there are some tiles that come close they might be debatable
so to me this makes sense that you cant terraform any tiles at the start this tech does not guarantee that you will be able to use it everywhere it will be useful on some planets but not all planets just like having better engines will be usefull on some ships but not all ships
I think the terraforming techs should always work on all planets
be careful what you wish for the answer to this might be to remove 3 or more tiles from every planet at generation to guarantee that one will be available for terraforming