[Aksarben]

Yes, they are asexual "budding" organisms, and just hoping for the best.  I know they have crossed, even in nature, as the Lager strains are Saccharomyces cerevisiae  x Saccharomyces eubayanus giving you Saccharomyces pastorianus, the hybrid.  However, it's an uphill battle since hybrid yeasts are sterile and are pretty much all budding or asexual yeasts.   We'll see.   The crossing happens when they become stressed enough.    Perhaps the Voss Kviek with it's ale properties, but able to ferment cleanly at higher temps will be the one to receive the genetic material need from the lager yeasts.
   
Also this link:  https://www.scientificamerican.com/article/scientists-make-the-first-new-lager-yeasts-in-centuries/

[Robert]

Very interesting link, Aksarben. At first not sure why you wouldn't just use Belgian ale yeast to get 4 VG, but of course this is just a proof of concept, more useful traits can now be bred.