That sort of thing is easily done in a vector drawing program which has a path-offsetting option.
Freehand is excellent for this, and Serif's Affinity Designer ought to have that.
One can do it in Illustrator as well, and I believe the feature has been added to Inkscape
- select outermost path
- Paste in place
- Path | Inset (do this as many times as are needed --- for some reason, one can't specify a dimension for it)
- draw in reinforcing elements and select them
- select reinforcing elements and inner path
The same concept should work in any drawing program --- just have to find the right commands / names / &c.
At one point in time, in Altsys Virtuoso in NeXTstep w/ its wonderful pop-up main menu system, the Difference command (Path | Combine | Punch) was a gesture for me (right-click, down a bit, right, right some more, release).
And now I'm sad.... drawing up the above in Inkscape was like torture compared to using Altsys Virtuoso.....