First, let me say that you’ve shown great work there and I don’t want to disparage it in any way. You’ve obviously put a great deal of effort into it and it shows.
That said, I still think that this falls into the realm of “just because you can, that doesn’t mean you should”. From my perspective, it’s about expectations from Blender as a tool. If Blender were to have more precision-style tools, there would be the expectation that Blender actually have high precision. It doesn’t. Adding support for that level of precision is a non-trivial task (I’ve looked into it… because I’ve wanted it too). This means that someone could sit down at a machine running Blender, see the precision-style tools, and then quickly become disappointed when it becomes obvious that those tools still aren’t actually precise. On some level, that’s actually worse than not having the tool because it sets a false expectation.
Sure, you might be able to get around that with good documentation… but that depends on people actually reading that documentation.
Like I said, I’ve wanted more precision in Blender myself. But if you want the tools, then you need the actual precision, too… otherwise, it’s like having a micrometer gauge that only measures in kilometers*.
*[sup][sub]Yes, I know this is a bit of an exaggeration. Hopefully you still get my meaning, though[/sub][/sup]
I have a feeling we have a crucial misunderstanding here. Nobody is talking about making triple digit precision technical drawings in Blender. There is however, a whole fleet of commercial apps and tools that give precision helpers in regular 3D space manipulation, thus enabling fast industrial or architectural design.
You say Free CAD? Did you try that thing? You think you could make dozens of design variations and output up to 400 preview context renders per project with it? Blender is the place to do it! I am not saying make a precise model of an engine part, ready for 3D printing or metal milling, i am talking about concept sketching with precision.
As an example, please check SketchUp, Fusion or precise modeling addon for Lightwave:
The same set is waiting to be implemented in Blender - measure length / angle / surface / volume with precision, move a cube from one precise point to another in one go, scale or rotate with fast pivot snap and precision, make dimension lines that you can show to the manufacturer.
Blender has it, you already have all the components! The example file above as well as NP Station is the proof. And i am not alone in this constatation - Andyrexic is working on it in Fluid Designer, mauge is working on it in Mechanical Blende, stephen_leger in Archipack addon and nBurn in xOffsets tools. Give those guys some wind in the sails, talk to them, organize them, hardcode their ideas…
To be specific, the features that could give some CAD flavor to this awesome program are these.