Man alive I thought I was the only one who regularly scours Migros across the cantons looking for these smaller british style Quorn sausages.
It's really hit and miss only certain Migros seem to stock them ever.
They have been stocked in the Migros in Metallistrasse in Zug - and this supply is reliable.
Closer to home in Zurich I can confirm they are NEVER in the Kreuzplatz Migros or the Migros at Stadelhofen
Recently however I did find a fairly reliable supply of these in the Migros at Enge station - I probably shouldn't be telling folks this as I guess now they'll all be snapped up

Also less reliably I have found them in the Migros in the main Zurich Banhof City underground shopping area.
I am going to go to Limmatplatz Migros now and will report back on the availability - if I find them there I am going to buy the lot - they freeze fine thank god
Will update as and when I find these