Converting <line>s and <use> into single shape/path

Question

I have a bunch of SVG images that are made in the following way: there is a “base shape” defined by a bunch of lines arranged in a tree-like fashion, that are cloned mirrored and transformed into a snowflake pattern with SVG’s <use> nodes. Unfortunately some applications do not handle thick lines and <use> nodes well, so I hoped to convert them to a more “simple” form of SVG with Inkscape.

Unfortunately, in their original form Inkscape seem to be unable to do anything with them: Path → Stroke to Path, Path → Object to Path, Path → Union or Path → Combine does not seem to do anything.

I figured out a way to do what I want, but it’s somewhat complicated:

1. Open SVG in Inkscape;
2. Save it as EMF;
3. Open saved EMF;
4. Select all;
5. Path → Stroke to Path;
6. Path → Combine;
7. Path → Union;
8. Save as SVG.

This way I end up with an SVG containing a single path like I want. Is there a way to achieve the same result faster?

Inkscape version is 0.92.2 if that matters.

The sample SVG looks like this (I didn’t find a way to insert SVG file as an image):

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="600px" height="600px" viewBox="-110 -110 220 220">
    <defs>
        <g id="primary">
            <line x1="0" y1="0" x2="0" y2="-100" stroke="white" stroke-width="10" stroke-linecap="round"></line>
            <line x1="0" y1="-20" x2="11.335980578361996" y2="-0.36550568466299893" stroke="white" stroke-width="10" stroke-linecap="round"></line>
            <line x1="0" y1="-40" x2="-23.342175588425484" y2="0.42983407834691434" stroke="white" stroke-width="10" stroke-linecap="round"></line>
            <line x1="0" y1="-60" x2="9.715489262346612" y2="-65.60924034092474" stroke="white" stroke-width="10" stroke-linecap="round"></line>
            <line x1="0" y1="-80" x2="-22.326108656091357" y2="-92.88998484255117" stroke="white" stroke-width="10" stroke-linecap="round"></line>
        </g>
        <g id="mirrored">
            <use xlink:href="#primary"></use>
            <use xlink:href="#primary" transform="scale(-1, 1)"></use>
        </g>
    </defs>
    <use xlink:href="#mirrored" transform="rotate(0)"></use>
    <use xlink:href="#mirrored" transform="rotate(45)"></use>
    <use xlink:href="#mirrored" transform="rotate(90)"></use>
    <use xlink:href="#mirrored" transform="rotate(135)"></use>
    <use xlink:href="#mirrored" transform="rotate(180)"></use>
    <use xlink:href="#mirrored" transform="rotate(225)"></use>
    <use xlink:href="#mirrored" transform="rotate(270)"></use>
    <use xlink:href="#mirrored" transform="rotate(315)"></use>
</svg>

Which renders to this (if the renderer understands SVG well):

Answer 1

The following should accelerate this a bit:

1. Select everything – Ctrl + A.
2. Unclone – Shift + Alt + D
3. Ungroup – Ctrl + Shift + G
4. Repeat steps 2 and 3 until nothing changes anymore.
5. Path → Stroke to Path – Ctrl + Alt + C
6. Path → Union – Ctrl + +