CartView cartDiscounts doesn't show ORDER_ITEM_PROMOTION_ADJUSTMENT, ORDER_UNIT_PROMOTION_ADJUSTMENT discounts

[diimpp]

When using promotion with Item percentage discount or Item fixed discount actions, then adjustments are applied on AdjustmentInterface::ORDER_ITEM_PROMOTION_ADJUSTMENT (or ORDER_UNIT_PROMOTION_ADJUSTMENT, didn't check) level.

In such case CartView

    "cartDiscounts": []

is empty, while totals->promotion is correctly filled.
(Do ignore non-standard output, this is artifact of my project)

    "totals": {
        "total": {
            "current": 12000,
            "currency": "EUR"
        },
        "items": {
            "current": 12000,
            "currency": "EUR"
        },
        "taxes": {
            "current": 2000,
            "currency": "EUR"
        },
        "shipping": {
            "current": 0,
            "currency": "EUR"
        },
        "promotion": {
            "current": -6100,
            "currency": "EUR"
        }
    },

Problem is with mismatch between adjustments levels for those properties.
Totals->promotion uses

ShopApiPlugin/src/Factory/Cart/TotalViewFactory.php

Line 26 in 8fe5f49

$totalsView->promotion = $cart->getOrderPromotionTotal();

which works by all three adjustment levels

     /** 
      * Returns amount of order discount. Does not include shipping discounts.
      */ 
     public function getOrderPromotionTotal(): int
     {
         return
             $this->getAdjustmentsTotalRecursively(AdjustmentInterface::ORDER_PROMOTION_ADJUSTMENT) +
             $this->getAdjustmentsTotalRecursively(AdjustmentInterface::ORDER_ITEM_PROMOTION_ADJUSTMENT) +
             $this->getAdjustmentsTotalRecursively(AdjustmentInterface::ORDER_UNIT_PROMOTION_ADJUSTMENT)
         ;
     }

and cartDiscounts only checks for order level

ShopApiPlugin/src/Factory/Cart/CartViewFactory.php

Line 85 in 8fe5f49

foreach ($cart->getAdjustmentsRecursively(AdjustmentInterface::ORDER_PROMOTION_ADJUSTMENT) as $adjustment) {

I'm going to fix this in my project and see how it will go, but so far it looks like an error, rather than design decision.