I mean the orange plastic "buffers" fixed to the legs of the cooking grid.
I do mean the cooking rack - one of two different heights.
Yes - apparently a discharge from the magnetron radiation?
I cannot agree to your assessment of the problem as the grids are intended for use when also microwaving. The availability of different heights of grid is to position varying sizes of foods to be more or less in the centre of the cavity when cooking, as detailed in the Baumatic instruction booklet.
Have you any further comments please?
I have provided you with a link to the Utensils Guide directly from the Baumatic Service Manual for the BMC450..Please click on the link and look at the bot***** *****ne....You may use the different grill stands / racks in bothe the Grill and the Combination settings, but NOT in the 'Microwave only' setting..You are correct in saying "The availability of different heights of grid is to position varying sizes of foods to be more or less in the centre of the cavity when cooking, as detailed in the Baumatic instruction booklet" but if you l'm sure that if you look a little closer in the manual that you have, you will find some indication that this is only for Grill / Combination modes and not for Microwave only mode.
Here is a link to the 'Utensils Table' that will assist you in using the grill racks during the appropriate settings.