Many moons ago when I was 21 after a very bad MC accident I bought a Reliant 325 Van and after a while, I put a SAAB 3 cylinder 2 stroke engine into this van. I know --- total madness --- but I kept blowing Reliant engines, and my mate had this SAAB engine for which I swapped a VW 1200 . I was actually thinking of fitting the VW engine in the back of the Reliant van but instead it went into the back of Mini Special. Anyway, my point is that SAAB had built a free wheel system into their gearboxes which stopped starving the engine of oil on a long downward hill. I think there must be lots of downward hills in Sweden. Wartburgs also used this system as the Wartburg engine was basically a Saab unit . In my case with the van, having had Ariel 2 strokes in the past I knew it was bad practice to starve a 2 stroke of oil on a long over run, so I just did not do it . As I did not use the Saab gearbox on the van I would have had to blip the throttle if there was ever the case of starving the engine of oil. But you just modify your driving to take this into account. Early 2 strokes were generally very oily and smoky and I can never recall anyone of having oil starvation. Trabants' I would assume fall into this category of having plenty of residual oil slopping about to not need to worry about starving it.
As a postscript to the Reliant saga, because I used the Reliant gearbox, I had to fabricate an extended gearbox shaft to fit into the Saab clutch and this kept ripping out, especially when the front of the van lifted off the ground from giving it too much beans. After that I went and bought a Vauxhall Victor for £30 ( Bench seats !! ) and passed my car test a week later.
