You do not write the document — you write its recipe once, and the document comes from the model every time.
Page size
Page size is declared, never inherited. It is A4.
A render reporting 612 × 792 pt went to US Letter, which is wrong. 595 × 842 pt is A4.
What a picture is
A view is the model, rendered. A figure is an image the model cannot produce. The insert forms and which supplied pictures are legitimate live on the recipe page.
Orientation
Portrait by default. A wide picture takes a landscape page, not a shrunken font.
How to insert
One view file per illustration, written in the recipe. The syntax is on the recipe page.
When it does not fit
Landscape first. If it still does not fit, the view is too large: split it in the model into overview and detail, as two views. Do not shrink the type, do not add a filter on the tag, and do not crop an export and place it as a figure.
Specified, not built
Print layout, landscape PDF, and embedded pictures are specified and not built. The current renderer does not emit a landscape page, and it does not embed a picture in the PDF — a figure comes out as a named placeholder. A render that looks otherwise is not from it.