Fusion Export Proportions Are Off
Stroke weights are sometimes interpreted incorrectly in Inkscape. This results in massively thick strokes that cause the file to render incorrectly.
To quickly check the file, go to: View>Display mode>Outline
This temporarily hides strokes and fills, and displays the actual shapes that Origin uses. If this view looks correct, select all the shapes and assign a 0.01" stroke width: Object>Fill and Stroke>Stroke Style: Width
You can return to the Fill/Stroke rendered view by selecting View>Display Mode>Normal
Scale is Incorrect
While SVG files can be defined in real world units (mm, inch, etc.), some vector editing applications (Illustrator, e.g.) convert these units into px (pixels). Unfortunately, different applications assume different pixel density.
Illustrator assumes 72 pixels per inch
Inkscape assumes 96 pixels per inch
Corel Draw assumes 72 pixels per inch
When opening SVG's in Inkscape that were created in Illustrator, the easiest technique to resolve scale is to go to:
File>Document Properties>display units = inches
Then change the file's scale to 72 pixels per inch.
You are then free to select the units you wish to work in.
Slow File Placement or Screen 'Lag' While Cutting
Large curved shapes become computationally intensive on Origin. To improve the performance on tool, shapes can be "flattened," ( turned into many straight lines). By controlling this in Inkscape you can find a balance between design fidelity and tool speed that suits you.
Select the curves you wish to flatten, then go to: Extensions>Modify Paths>Flatten Beziers
The image above shows a bezier circle, and the output of the flatten function using three different settings. Keep in mind using a value that is too small will create many lines and will eventually slow down the file in much the same way as the original bezier.