Occasionally I get asked if there is a way to define the actual letter-height instead of the slug-heigt.

Only if you know the proportions of e.g. cap-height to slug-height and enter something like "12pt * 0.671". That's obviously a bother since you first have to find out that proportion.

A script can do the maths for you, as usual.

Sometimes after you finish an elaborate search you might want to get back to the page you started the search. But how to get there?