Well that was fast! Seems to work well, and fits perfectly my use case. Thanks a thousand! One thing might be difficult for a beginner; namely there is no visual cue if the viewall button is active or not. I think usually one would go for a select/deselect button that is highlighted when active. The same goes for the older but similar hide frames and points button. At least for beginners it would probably be much easier to understand what's going on with visual clues on the toolbar, too.
I hope that also a similar new tool for adding a cosmetic line between
two points could be added for v0.19, as well as a new cosmetic bolt circle tool. If I remember correctly, some people have asked for a bolt circle tool in TechDraw. I guess in some cases there will be a problem to find the center point for the bolt circle in techDraw. Luckily utilizing cosmetic points it'd be possible, albeit somewhat clumsy, to simply add a point to the exactly right coordinates. Difficult but possible would be much better than impossible!
EDIT: Now that I think about it, an obvious way to make a bolt circle tool would be to demand the user selects either one point (center, with editable radius), two points (center and radius) or three points (all three on the circumference, as this exactly defines a circle, and should be the most useful choice for a bolt circle). Making the tool accept three edges, or one point and an edge, or even an existing circular arc, would add some extra choices, but might probably be an overkill.
OS: Debian GNU/Linux bullseye/sid (KDE//usr/share/xsessions/plasma)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.17439 (Git)
Build type: Release
Python version: 2.7.16
Qt version: 4.8.7
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/UnitedStates (en_US)