Around the time Windows 95 came out, there was a push for all the people in the call center to get the "OS/2 Certified Engineer" rating, but IBM shut down OS/2 before anything much came of that. I got mine at the '95 Comdex, while doing volunteer support for Team OS/2. Still have the little plastic card...
But yeah, most of the level 1 guys didn't have any experience with OS/2 and a few didn't have any experience with computers, when they started. About 90% of the problems that came in were for similar issues though -- printer stuff and video problems seemed to be the most of them. I still have the command line command to reset the video drivers to VGA burned into my brain. I could actually fix your shit for a wider range of problems, if you were lucky enough to get me, but fixing your shit is time consuming and I was frequently in trouble for not answering as many calls as I was supposed to be. A lot of the techs just wanted to throw a reboot-requiring command at you and make you go away so they could keep their numbers up.
Funnily, even though OS/2 sported newfangled "threads", very few IBM applications used them -- most IBM OS/2 programs were pure windows ports. Ironically, if you ran the windows versions of those programs, you could run them in separate memory spaces so that the programs couldn't interfere with each other when doing processing in the event-handling thread. So Windows programs ran better on OS/2 than they did in windows and better than OS/2 programs ran in OS/2. You could format a disk and run a print job at the same time, as long as you did it from the command line. The GUI versions would tie the system queue up, so you could only do one at a time.
Last time I left was in 2005 in Colorado. At the time, they would just throw a bunch of people in a room. They were nice enough to throw up some half-cube walls so we could face the wall and get some semblance of a distraction-free environment. They still think they can pay well below market rates just because they're IBM, even when they're hiring you on as a third party contractor and even though their FTE benefits program is only marginally better than the third party contracting houses are offering these days.
The tree of research must from time to time be refreshed with the blood of bean counters. -- Alan Kay