Only one perimeter

[espr14]

There's single perimeter for top solid infill. But it is useful for bottom solid infill and bridges as well.
Bridge overlap works for infill only so removing extra bridge perimeters makes sense.

[supermerill]

for the bottom, you mean for every bottom or only on the first layer?

[espr14]

Are there other bottoms than first layer? Other bottoms are sliced as overhangs (bridges).

[supermerill]

All surfaces that don't have a layer printed below is considered as bottom. If you use a dissoluble filament for support with 0 offset, they are treated like on the build plate.

[espr14]

It makes sense for them as well.

[GrubbyZebra]

yes, please!