SVG IDs don't match layer names

I would also like to be able to programatically pick out layers from a document by ID. While the "inkscape:label" tag gets saved with the name when saving to Inkscape SVG it seems that the layer name (or a calculable similar name) should also be stored to the "id" tag for plain SVG documents.

No. "id" elements must be unique in the entire document, etc., whereas layer names should be duplicable. Making the id more visible might help.

I was about to report the same thing. If layer names aren't required to be unique (which I agree with), then set them as the object's name rather than ID. I noticed this with optimized SVG, but it's an issue with plain as well.

I confirm the behavior.
When saving as plain svg, layer names (choosed by user) are removed to keep only layer ID, with no link to layer name.
Having a link between layer name and layer ID would help with later layer name handling.

Hit this today. Same logic - programmatic editing of the output SVGs is difficult if layers aren't saved with IDs - please let us edit layer IDs, or copy the layer display names to the output layer IDin the output optimized SVG

sorry, I should have noted: there is a workaround.

The layer ID is exposed in the saved 'native' SVG:

  <g
     inkscape:groupmode="layer"
     id="layer2" <<<< not editable from UI
     inkscape:label="Guides" <<<< chosen in UI
     style="display:inline"
     sodipodi:insensitive="true">

if you edit the ID manually in the SVG file,

  <g
     inkscape:groupmode="layer"
     id="Guides" <<<< manually edited in SVG
     inkscape:label="Guides"
     style="display:inline"
     sodipodi:insensitive="true">

... then inkscape will load / edit / resave the document without changing it.
So it seems programmatic editing of the output SVG becomes possible.

Perhaps this will help others.