How can I update my manual table construction for 0.14.0?

I created some convenience table functions to make headers automatically fill colums (this is for recreating a template in Typst), but now some cases started breaking in Typst 0.14.0. The code basically takes the table apart and recreates the children.

The code is quite long, so I put it onto a project in the webapp.

Is there something I can do to make this work again in 0.14.0? I have found nothing related in the changelog, is this a regression?

I was able to reproduce it with a smaller example. The following compiles with 0.11.0 to 0.13.1, but not 0.14.0:

#show table: it => {
  // Collect old data
  let fields = it.fields()
  // Children have to be treated separately as they are given as positional arguments
  let old_children = fields.remove("children")
  let children = ()

  // Style table cells
  let modified = false
  for c in old_children {
    if c.body.text == "A" {
      modified = true
      children.push(table.cell(colspan: 2, [Blub]))
    } else {
      children.push(c)
    }
  }
  // Prevent infinite recursion
  if modified {
    // Rebuild table
    it.func()(..fields, ..children)
  } else {
    it
  }
}

#table(
  columns: 2 * (1cm,),
  [A], table.cell(colspan: 2, [B]),
)

Older versions produce

test

while 0.14.0 throws

error: cell's colspan would cause it to exceed the available column(s)
   ┌─ test.typ:31:7
   │
31 │   [A], table.cell(colspan: 2, [B]),
   │        ^^^^^^^^^^^^^^^^^^^^^^^^^^^
   │
   = hint: try placing the cell in another position or reducing its colspan

I also opened a bug report, but is there any workaround?