>I don't know for certain how true it is, but there's a legend that ELWRO prepared a design based on their best, but compatible with S/360 and thus rest of ES EVM - just way faster in smaller frame (effectively imagine top-tier S/360 CPU but in way smaller package)

Wasn't that produced as R-32?

My understanding is that while R-32 did benefit from the technology edge that ELWRO built up, they actually tried to build a much faster model than R-32.

Unfortunately, it's really hard to get reliable sources about some details.