The way I get around RPM loss is to use the 240D's dash mounted idle adjustment. I just tune it for the best rpm drop and idle speed.

When my engine is cold the RPMs drop real fast. So a high setting helps this and the higher idle warms the engine faster.

Hot, the drop will be just right when my idle is at 700rpm.

It's ok with me since I don't mind tweaking the idle knob every now and then.