For plant health, I don't think it matters where the scion is placed.

For grafters, it's often easier to graft higher on the trunk of the rootstock, especially when the scions have very short internode distances. But most buyers prefer to buy plants with foliage as close to the ground as possible. So most grafters make an effort to graft close to the ground.

For standards or lollipop conifers, they are almost always top grafted. That is because these are typically dwarf selections that grow slowly and never develop much of a trunk on their own. So the tall straight trunk you see is some other compatible conifer with the dwarf lollipop cultivar attached at the top.

It is very much a personal taste thing but I find them to look very unnatural.

I'm thinking about trying a IceBreaker in a container. Thinking standard -shorter 9-12" trunk just to stick the head of the pot a smidge. I think the head being perched a smidge higher in a container looks better. The container is about 22-23" high.

Figure since the conifer will be about 4" lower than the edge of the container, the standard will just elevate the head out of the pot a bit nicer

The hard work is finding a standard head on Firma. The only one I have found on standard is on balsamea

Figure since the conifer will be about 4" lower than the edge of the container

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why dont you fill the pots another 2 or 3 inches.. whats the advantage to 4 inches?

I always like to keep a smidge of room in containers. Keeps the potting medium in there, instead of just spilling out.

Earthquake in Equador and Peru: Respect for the victims

TV pictures show beautiful, beautiful street trees that are grafted on 4'-6' standards.

Again, respect for the victims of the earthquake.