It's widely accepted as something you need to do with any transplant - whether you're digging it out of the ground, up-potting it, bare-root planting it or otherwise. Anything that impacts the roots, specifically, you need to give the plant a chance to recover. Usually 3-6 weeks is enough to allow a plant to recover, but every plant is different. Watch for it to show some 'leaping' (showing new growth) before even thinking about putting it in partial or full sun.
Understand that being in full sun is a LOT of stress on a plant, causing a LOT of evaporation. Roots are the hydraulic "pump" supplying water to the leaves, so ... damage or disturbance to the roots interrrupts that flow of water to the top of the plant. Placing a plant with recent root stress in full sun means it will risk evaporating more water than it can uptake via the roots. If you put the plant in the shade or indirect light for a couple of weeks, it allows the plant time to "rebuild and recover" before being placed under the strain of full sun.
You never know what conditions plants were in before you got them, I like to slowly acclimate them to sun if I didn't physically see where they were previously. If a plant was in a shaded nursery and you put them in full sun, you will see 'leaf scorch' (sunburn), which usually presents as tan or off-white blotches that usually result in flaking off of leaf material etc. (it's usually not fatal, but will set the plant back).
I can't answer your question about the Smith. I wouldn't feel comfortable giving you an answer without actually seeing the plant with my own eyes (or the view of a camera lens).
:)