Did you too find no way to replace the id-values auto-generated by Inkscape with your provided inkscape:labels?
Here's a program which does it.
Warning
I only tested it on one of my SVGs so far. If you are experiencing problems with running this program on your SVGs please open an Issue.
Replace id-attribute values with the values of inkscape:label within SVGs created with Inkscape
cargo run /path/to/input.svg /path/to/output.svg