Dear AS,
Laminated sides are well represented in classical construction and almost never in known makes of steel strings. Thus I am sampleless in order to do any A,B with similar guitars. It would certainly make the sides stiffer, though that is what we are manipulating when we use different hardwoods in the sides and back. If I was to extrapolate, which is all I can do for this question, I’d say that using woods in laminate that are denser in combination would lend brightness to tone while lesser density lessens clarity.
I pair woods for their combined density to manipulate the clarity of tone, in this back and sides are both important.
Old Growth is a subjective term, I’m going to use it to describe virgin, or an unmolested ecosystem that allowed trees to grow at steady rate, not accelerated by opening the canopy to nourishing sunlight. These trees would accordingly be denser than ones that grew quickly when unnaturally exposed to excess sunlight. These latter, fastgrowing trees will have wider annular rings and less stiffness. We just learned above the effects of more or less density on tone.
All the best, Richard