On a past project, I ran out of enough dry flat-sawn douglas fir to make some built-up legs for a workbench, so I was delighted to find some kiln-dried DF at the local lumber yard. However, it was "vertical grain" (i.e., quarter-sawn) DF. I'll confess at the time, it did not occur to me that the two orientations of wood might have differential movement, so I happily laminated the two types of DF together to make the leg. Two years have passed, and the leg is holding together fine, but I'm curious if this is a really bad practice.
I think one thing working in my favor is that the local climate doesn't have a big seasonal indoor humidity swing. But, aside from theory, has anyone ever seen this type of lamination (quarter-sawn to flat-sawn) actually fail?