Since Theo22 has been shy about posting in the discussion, I'll just spill the beans.
In PM's with Theo22, he basically confirmed they have been using stall strips on their human powered velomobiles. Except they call then "Storm Strips".
I Googled the term and found at least one Dutch blog. Using Google translate you can read the Dutch blog. The translation is a bit rough but with effort, you can glean the basic meaning.
Google Translate
Another blog is here with Google translate. Again, the translation is a bit rough.
Google Translate
Earlier I stumbled on another page which I believe is Theo22 and Allert's velomobile company in which they (re)sell the strips. I can't find the page again. If I do, I'll post it.
This Dutch discovery basically proves that stall strips are at least one aero fix to streamlined motorcycles.
There must be more though and we should continue looking.
-- Teri