Build a platform report

use Cbox\Nexus\Contracts\NexusEngine;
use Cbox\Geo\ValueObjects\SubdivisionCode;

$states = array_map(fn (string $c) => new SubdivisionCode($c), $sellerSellsInto);

$report = app(NexusEngine::class)->report($states);

$report->needingAction();  // list<NexusEvaluation> — crossed obligations AND unevaluable states
$report->approaching();    // watch
$report->registered();     // already handled
$report->notApplicable();  // DE, MT, NH, OR — nothing to comply with
$report->forState('US-CA');

Feed needingAction() into your platform's alerts and onboarding, and approaching() into a watchlist so a seller sees a threshold coming before they cross it.

Do not build the board from triggered() alone

needingAction() exists because the obvious dashboard — render triggered(), approaching(), registered(), ship — has a failure mode that looks like success. If the threshold dataset is unreachable, or no SalesLedger is bound, every state resolves to Unknown. All three of those buckets come back empty, the board is green, and the seller under-collects nationwide.

That is the exact failure NexusStatus::Unknown was added to make visible, and a consumer that never asks for unknown() puts it straight back. One call that already includes them is harder to get wrong than four you have to remember.

// Surface WHY, not just how many — the reason names the seam that came up empty.
foreach ($report->needingAction() as $evaluation) {
    if ($evaluation->status === NexusStatus::Unknown) {
        $this->alertOperator($evaluation->state, $evaluation->reason);
    }
}

Verdicts may also carry caveats — things the engine relied on but could not verify, such as a ledger that never declared which sales it counted. Show them next to the status; see the decision model.