Mike Burrows , UK Bike design Iconoclast , build a Long wheel base recumbent, head tube was vertical
, trail was The Offset..
so like a low trail , you didn't have to lift the front of the bike going off center..
but the trail was larger..

I think Powells carried his Book on the subject.


But I realize the Bike Biz is conservative. front wheel is in the same line as the rear.
Mike was, It seems, OK with them being on parallel lines.