Hot and Dry aren't the adjectives associated with fear of summer repotting. Unless you don't water.
Hot and Windy.
But then you can still water.
Ask
@0soyoung the actual temps at which roots stop growing.
Keep in mind that is watered root zone temps that you can maintain.
Then, the fear of spring repotting Spruce is apparent. They are trying to grow on top at that time. Why stress them?
Don't fear summer repotting of Spruce.
As far as which should come first.....
Define "regular soil".
Here, the only things that MUST be potted (planted in the ground actually.risk.) are balled and burlapped trees from what is usually clay. (And don't quote me on that must, but for me it is)
A tree in Nursery soil is set up to grow well and will for at least 4 or 5 years.
Which is plenty of time to style, recover, then repot.
Inspect the roots.
The only ticking time bomb is....
Will the roots get too hard to unmess before you get to them?
The rest is up to what the design encorporates.
Styling via wiring every branch is different than styling via cutting off 80% of the foliage.
Think of the top too, and it's ticking time bombs.
If there is a heavy section that is going to get worse before the tree recovers enough from repotting to deal with said heavy section, perhaps you MUST cut heavy and therefore "style" now.
PPB.
Keep potential problems at bay.
Sorce