Flex comes to mind. It’s from Paul van der Laan who helped with Kievit. Can you talk about the reasons why FF Kievit won't work for you?

Hubert Jocham’s Safran is another, slightly more broad-pen-flavoured option. The family spans 9 weights, and also the italics have a double-storey ‘g’. There’s a Pro version with small caps and extended language support.
But Stephen’s right: without knowing why FF Kievit is out of the question, it’s impossible to come up with suitable alternatives for you.

Thank you, Stephen. Thank you, Florian.

I don’t really know wether or not Kievit will work. I guess it will. I’m looking for a sans serif (with no or at least modest modulation) that is neutral and clear. It has to serve two purposes: (a and most of all) to work well as a headline typeface together with FF Scala (, Minion and Albertina) as body text typeface; (b) to work as a body text typeface as well (good legibility).

I’m just a non-professional, and I’m just interested in typography for my own purposes (typesetting scientific texts). Hence, I like to be sure, that I’ve chosen the ›right‹ font, before I purchase a license.

You do know that FF Scala is a superfamily that includes a perfectly matching Scala Sans?

Yes, I know. But Scala Sans—a wonderful typeface—reveals in my opinion too much character in taller sizes, at least for my purposes.