Yep, SVGs are the way to go for all symbols at the moment (although I would argue into the future as well). To create SVGs and edit them, I use the open source vector editor Inkscape (very close in features to Adobe Illustrator, without the price tag)
I use Label components with css borders set to make my pipework - I use either single-edged borders or right-angled borders. They work pretty well.
Nader will often create all of the pipework as an SVG and then place device view templates where they need to go (or so I believe)
Perspective drawing tools are “Coming soon”, as they say…
Example:
