How to make a different margin depending on a page number?

I am trying to emulate the style of Tibetan pecha. These books typically have different page margins and decorations depending on the type of page.

The important point is that this should all work as running text. I cannot have seperate page calls for each page of content, including the title page and the alternative layout.

My implementation is already very janky, since I cannot have horizontal headers and footers, I can’t have multiple of them in different layout spaces.

Additionally, I cannot seem to find a way to emulate the start of each page, which is supposed to contain a yig mgo (༄༅། །) within the running text.

Here is an example I made with gibberish in PechaMaker (red are title pages, green are special pages, blue are body pages):

Currently I can only achieve this (again, gibberish; Note: the title pages have too many lines, and the special pages and body pages don’t take up the full space.):

Is there any way to do this? This is quite necessary for pecha.
(Also is there any way to do the yig mgo at the start of each page?)

Additionally, it is common for these to wrap around image pages as seen below: