I was there back in the old days, and the example in the interview of "There are a number of applications where multitasking on a single user system could come in very handy. Here’s an example." were very artificial marketing driven.

In the 80s I would do things like file copy and printing to a serial port-attached printer in the background and I/O was bulletproof I don't recall ever having a problem on Level 1. It was slow and the floppy controller halted the computer severely but it never lost data or crashed, very nice.

On Level 2 I used Multi-Vue to run various combinations of editor, compiler, and executable in windows.

The main problem I had with OS-9 Level II and the dev system and Multivue is the complete software pack from Radio Shack was about $250... to run on a computer with a list price of $200... These were also the days when your CRT monitor and your hard drive (if you had one) typically cost 2x what your computer cost.

Another interesting quote from the interview was regarding a million cocos sold and only 100K disk drives sold by RS ... Note the base coco was $200 and for all practical purposes only available from RS, whereas the RS disk addon package was $300, a hundred dollars more than the base computer, and in comparison Rainbow/Hot Coco magazines were full of ads for cheaper floppy packages, like $225 to $250 price range.

Its interesting looking at old PDFs of Rainbow from the late 80s, I never noticed it at the time but 1/3 of the ads were for IBM/PC/XT compatible hardware, which seems weird for a "coco" magazine.