Nice one IvanK!
Is it known if the DB 601 'Aa' or 'A' engine is modelled in the E-4? Unfortunately, I don't know what the min governed RPM for 601s was, might as well be lower than 2000RPM. It is great to see all these small issues being addressed and fixed (mind you we started with a E-3 with lever not returning to the central position and now we have got a working Luftschrauben-Verstellautomatik
)
In order to fine-tune the FMs, it would be great to know which engines and which propellers are being modelled for each subvariant. Easy enough with the propellers - 9-11081E for E-4 and 9-11081A for E-1 and E-3, but the engines in E-4s did quite a difference regarding max ATA / RPM, from which appropriate RPM drop could be calculated as the pilot moves the throttle back gradually.