Setting the options property used to tear down and rebuild the component, snapping an open dropdown shut and resetting scroll / search. It now updates the live picker in place: an open dropdown stays open and the selection, scroll offset and search term survive the swap — so handing the component a fresh array on every framework re-render (React / Vue / Lit / LiveView) finally works for multi-select. Set options to null to clear in place; call refresh() when the same objects mutated; opt into dropping vanished selections with prune-missing-selection. If you relied on reassigning options to reset UI state, do that explicitly instead.

In a multi-select tree, checkbox-mode now defaults to cascade (was independent): checking a branch selects its whole subtree, branches render tristate, and the emitted selection follows cascade-select-policy (default rolled-up — a fully-selected subtree collapses to its root value). Behavior change for existing tree consumers — set checkbox-mode="independent" explicitly to keep per-node toggling. No effect on flat lists or single-select (cascade only activates in tree + multiple). Everything else in 2.2.0 is additive.

onSelect/onDeselect/onChange used to receive the bare option. They now receive a CustomEvent<MultiSelectEventDetail>. Read e.detail.option, e.detail.selectedOptions, e.detail.selectedValues. The native addEventListener('select', …) path is unchanged.

The input is now a flex field with real sibling controls (counter, clear, chevron). Removed: --ms-input-padding, --ms-input-padding-right, --ms-toggle-right, --ms-counter-offset, --ms-input-clear-inset, --ms-input-clear-gutter, --ms-transform-center-y. Use --ms-input-padding-h and --ms-input-gap instead.

Rendered from --ms-icon-check/--ms-icon-indeterminate rather than rotated borders. --ms-checkbox-checkmark-thickness is now a no-op (stroke is baked into the SVG).

Previously a fixed 32rem. Set selected-popover-width / --ms-selected-popover-width to restore a fixed width.

--ms-rem is now var(--base-rem, 10px) and icons flow from --base-icon-*. No change if you don’t use a base layer; a theme can now rescale/reskin everything centrally.