[.....]
If you could manage avoiding ‘cooking’ with a a ’one-part series’ (Schemes 3 and 4), that would be GREAT. Then I would not even mind if I could not understand its working :-)Hehe. This would need a new command in groff, and I'm not sure whether it's worth the trouble.
[....]This could have been an opportunity to put some more serious graphics into groff, but
that's your call. Anyway, many thanks for your help. Miklos