The blog post describes the problem being related to the size taken up on the stack thanks to the increased pointer size, I assumed running in x86 mode would use less stack space.
I was just wondering whether it would make a difference on x64 since maybe all windows are handled as 64-bit inside the kernel, but I am no expert on kernel stuff so I don't know whether that is true or not. But since our app is already running as 32-bit it is somewhat irrelevant in this case.
Here is an interesting KB article that is somewhat related. It is a hotfix that limits nesting depth in XP to 50, preventing a BSOD that previously occurred due to too deep nesting. The fact that there are actually applications that try to create "up to 100 nested windows" just points out how woefully inadequate the 7-15 levels in x64 is.
As far as I'm concerned, if the design limit is 50 but Windows can't even get close to it (and silently stops working), it is a bug. If I create the 8th child window without any error, but Windows then can't manage that window properly, it is bug.