How to merge multiple shapes into one in Visio?

Question

Visio

Given:
I have a complex figure, consisting of many elements. I want to combine all these elements in such a way that the figure is displayed as a single whole without components.
In visio, in the Developer-operations section, there are not quite correct functions that will change the shape beyond recognition - cut out colors, erase lines, etc.

Why I need this:
I have dozens of similar shapes from visio that I would like to import into diagrams.net for diagramming purposes. But the problem is that shapes are imported with all layers and constituent elements, which leads to the fact that double-clicking on a shape will necessarily select some small thing instead of editing the name, which is annoying and interferes with work. Grouping elements does little to help with the problem.

Herelink to .vsdx file (Google drive)

Answer 1

I saved each element separately as a vector image, and then threw each shape into draw.io.
There, this element was displayed as a whole. Some elements had to be edited separately, as the draw.io service often cuts shapes at the edges.
The curve and oblique method, but somehow it worked.