The
gj thread got me thinking about how serious of an issue is the overlap of different letters. I imagine this is a wide topic - it may cause issues on some systems, for all I know. I can immediately think of one case that is not insignificant: letters made for outdoor advertising. If there is a collision, a designer would have to clean it up and weld the text aesthetically before it gets... um, welded in metal. If this has to happen every time the font is used, this could lead to dropping it in favor of more composed fonts.

(This would probably be a good time to go on a tangent and ask if FontLab can measure Bezier length in cm.

Corel had an option for that in the past, but I haven't used in ages. FWIK, Adobe Illustrator has to use a plug-in, not to mention the AI canvas is restricted in size.)
Comments
I don’t think collisions are always bad, things like AA and rt can overlap and it can look great in a headline or a logo. But they can also look like shit depending on the context. So I leave it up to end users to crash letters together themselves.
So during deliberative reading there is a conscious appreciation of form (which is what makes almost any collision objectionable) but in immersive the subconscious doesn't mind the form, unless the *texture* is disruptive (or too unfamiliar) so you can let things touch, judiciously.
BTW regressions are actually an indicator of immersion. While in deliberative your eyes can dart around the letterforms, which never happens when immersed.