In between exposures, DSLRs open up the aperture blades and then close them again for the next exposure. This is presumably to allow autofocus and metering in between but leads to aperture flicker in timelapse video and consequently the 'fix' of twisting the lens off the electrical contacts. It happens even if you keep the Depth of Field preview button held down constantly.
If the camera is set to manual exposure and manual focus (so there is no need to meter or focus), could the camera be forced to leave the aperture blades in their stopped down position between exposures so that aperture flicker does not occur?
Ideally, you would still be able to change the aperture setting occasionally and have the camera adjust to match, but if the aperture setting is the same as previous exposure then leave the aperture blades at their set position.
This would allow Bulb Ramping with a series of aperture changes as needed through twilight but no aperture flicker during each set of exposures where the aperture setting is not changing. Possible?