The idea of D2986/rP24021 was that outposts have only enough vision range to show themselves, but not to reveal their surroundings; posting a soldier would do that.

In rP24779#48517, @Nescio wrote:

The idea of D2986/rP24021 was that outposts have only enough vision range to show themselves.

Yes, this addresses that they didn't really have enough vision range to show themselves.

Wasn't 4 enough? That's the tile size, isn't it?

The problem was that they needed more when stuck between four different tiles which might look weird in some cases. Another Los issue

In rP24779#48520, @Nescio wrote:

Wasn't 4 enough? That's the tile size, isn't it?

Yes. Obviously it was not, since a player reported it as bug, and further as you yourself noted on another diff, this still left outposts in the FOW because of a separate bug.

If 4 isn't enough for outposts, then it's probably not enough for walls, palisades, obelisks etc. either, therefore the correct template to change is template_structure.xml, not the outpost.

In rP24779#48524, @Nescio wrote:

If 4 isn't enough for outposts, then it's probably not enough for walls, palisades, obelisks etc. either, therefore the correct template to change is template_structure.xml, not the outpost.

Disagreed. Players are not surprised that walls do not give vision, they are that outposts do not give vision. Further, wall towers give vision, meaning in practice this isn't a problem at all.

Further, wall towers give vision, meaning in practice this isn't a problem at all.

Only for city walls, not for siege walls or palisades.