Wrap two to five kit-buttons in <div class="kit-button-group" role="group" aria-label="…">. For a group where each button turns something on or off independently, give the buttons aria-pressed. If only one can be chosen at a time, use the segmented control instead.
Accessibility
role="group" with an aria-label names the set ("Text alignment").
Toggle buttons use aria-pressed="true" or "false", so screen readers announce "pressed".
Each button stays in the tab order; the group doesn't change keyboard behaviour.