Different aspect ratios

Many thanks for your answers to my previous two posts.  I successfully created a 6-minute 4K DCP and projected it in my local theater.  No problems, looked great.

Could you answer another question - I now want to make a longer DCP with more of my data files, but I have a number of different aspect ratios.  Can I mix aspect ratios in the Input Directory?  The DCP I made had tiff files with 3:2 aspect ratio, and OpenDCP filled the screen vertically and filled in the Left and Right edges with black.  If I now mix in files with 4:3 and 16:9 aspect ratios, will OpenDCP automatically letterbox the 4:3 with (wider) black edges, and fill the whole screen with the 16:9 files?

(I found for example with Quicktime, it seems to set the aspect ratio from the first files, and then distorts the following files that have different aspect ratios.)

I could try this by trial and error, but I do not want to wear out my welcome at my local theater!  So your advice will be greatly appreciated.

Robert