The root of the paint-over and of the keyboard regression rega's A/B found.
ProfileLoader's wrapper is min-height: var(--profile-min-h, 100dvh), and a
host that already sizes the element sets --profile-min-h:0 (the Gallery's
.dms-pane, VerticalTabs, plugin-studio). The pane column sizes each element
(inset:0 in its pane) but never set it, so on the standalone leaf each
pane's wrapper was 100dvh = 900 px inside an 843 px pane: the wall's
scroller ran 57 px past its pane, its first row's tapes painted over the
map, and Tab into those tapes scrolled the pane COLUMN (and, with the
clip, onto an invisible control). The Gallery was pane-sized only because
its own host set the variable. The clip stays as belt and braces.
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