Calling Dome.Slew() with slaving disabled does nothing, no error. It appears that it was originally written for slave-slewing, but it really isn't used for that. No one used it until I needed it for the panel/screen enhancement to flats in ACP-667.
Another bug in Slew(). If no optional Altitude argument is given, it still tries to slew to 0 (the default for the optional arg) and it won't do this with the shutter closed. Must be able to call Slew() with one argument only and have it skip the SlewToAltitude().