Very briefly, this is my personal thinking:

Voice opening is a complicated matter and depends on a lot of things and many times controversial.

The wood.:- Because the top of the guitar affects the sound most, therefore the top of the guitar is most important. We should then concentrate on the top wood.

Laminated – Normally only changes a little bit if any at all.

Solid wood – depends on the type and age of wood.

If the wood has been aged for a long time, most probably the sound would be a lot easier to open up.

Sitka Spruce and Adirondack Spruce will change significantly with time. Engelman Spruce and Cedar change very little.

That is a very short but I think its quite enough guidance (general rules) to go for.

Hope that helps.

Rod