In firmware 225.0, we added a second channel, Engine Revolutions After Delay, to solve the original issue. (Please note that the channel is 16-bit, so it only counts up to about 65 000 revolutions - suitable for cranking)
In Client 225.0, we also fixed this “signed/unsigned mismatch” issue. It works with any firmware.
New software update is available here: EMU PRO software 225.0-beta