How to duplicate a group of objects in Planet Coaster

After lots of experimentation in sandbox mode I think that I can say this:

• Every building part and scenery object has a scene value and an effect radius. These values can be vastly different, but do not necessarily correlate with price or size.
• Each of these objects affects all queue tiles within its radius. The total scenery value of each queue tile is the sum of the objects which affect it.
• Effect radius is limited horizontally but not vertically. That means scenery can be placed far above or below the queue and still affect it fully.
• The scene rating of a ride is the average of all tiles of its queue.

That means in effect:

• Rides with short queues are easier to style than rides with long queues
• Compact and winding queues gain more score from each tile than long, stretched ones.
• Placing scenery very close to the queue is good for two reasons. First, more scenery objects can affect the queue and second, each object will affect more queue tiles.
• When you don't care at all about aesthetics or realism, you can move all the scenery exactly below the queues and a hundred meter below ground.

Update Version 1.1.3: While the patchlog says that "Various improvements have been made to how guests assess ride queues", none of these seem to have invalidated any of the above points.

The 2017 aniversary update (Version 1.4) added tooltips to all shop extras which tell you how they affect the consumers. Note that not all effects align with your business interests:

Extras also directly affect the monthly running cost of the shop. This is not shown on the "Items for Sale" tab, but you can see the effect if you switch to the "Finances" tab. It appears to be a fixcost unrelated to how much the store actually sells. Some extras even reduce running cost. For example, adding "some" ice cubes to the Green Slush in the previous screenshot reduces the running cost of that slush shop from $212 to $209.