Hey, sorry I didn't emphasise enough in which way we've used it in the teams. Yes, at glance it might look complicated, and to some extent it is. That's why I built the framework that I mentioned is available on GitHub, so that you can focus on just playing around with type and proportions, and disregard the maths.

To expand a bit on the benefits, it really kicks in when you look at a longer product lifecycle. Instead of ripping apart old school design documentations with hard pixel values just because you changed that one rule about margins that is apparent everywhere in your design, you simply update proportions.

Like I wrote in the end of the article, I personally find it more usable to say “Let’s use two base units between paragraphs" than “The distance should be 48px on small, 60px on medium, and 72px on large. No wait, sorry, we changed that. It's now 36px on small, 54px on medium, and 80 px on large”. So far, that has also been the experience of the teams I've tried it with, and clients I've previously helped since they can use the units to build new elements that we didn't know was needed during a time boxed projects, but became apparent in refinement work. Sure, you can do that with documentation and living style guides, but RWD has really stirred things up.

However, just because this works for me doesn't mean I in any way would think it does for everyone else :)

It's still up to the users to actually activate the content blocking. Apple enables it, but the choice is still yours to make.

I've tried FontExplorer X, and changed the source option for my Font Library-folder that the app uses to organise the files to be located in my Dropbox. Worked like a charm.

Oh, I hope that you can! Referring to the (Flinto example in the OP. In Flinto, I simply have the two art boards and the applications does the rest (except for fine tuning of course). When I try to do this in Principle there is a lot of duplication of elements going on. Hopefully, I'm doing it wrong :P

Oh I will, no doubt about it. It would just be nice to have one resource when I do usability studies.

Having several is no biggie for design collaboration.

The original question here probably regards expecting a similar behaviour of an application like Photoshop, where the layer would align according to the bitmap information. However, this isn't optimal because the alignment is dependent on what characters are used in a text layer (e.g. "amy" would not align similar to "elk" because of the difference in ascender height).

But stating "Yes but the edge of the text box is where browser believes this text to start" isn't true simply because Sketch renders leading the same way Photoshop does (i.e. increasing the distance from the baseline upwards, instead of up and downwards from the centreline like in CSS's half-leading). Placing a text in an element, similar to "John K. Fitzgerald" wouldn't look like it does in Sketch, if the line height is increased.

For this the hold true, they should then change the default way line-height is rendered. But then again, that would probably be unbearable.

Oh, I've answered this question in part on Medium. I think this link gets you there: https://medium.com/@psilfver/no-one-is-more-happy-than-i-am-that-you-raised-this-question-we-did-put-a-lot-of-thinking-into-it-1c7a9368d918

Oh, sorry if that was in any way unclear — but the whole point was not to get disturbed by things happening all over the place that you probably have no interest in (mentions in social media.). This would be fully curated and up to you, just as you decide how aggressive Calendar reminders are today. More on the "The game starts in 10 minutes" end of the scale rather than "Someone mentioned you on Facebook".