Magento 2.4 - add custom discount amount and tax amount to each cart item when an order is created programmatically

Question

I'm creating an order programmatically and I would like to add a custom discount to each quote item.

I have something like this ...

$quote = $this->_quote->create();
...
foreach($products as $item) {
....
   $quoteItem = $quote->addProduct($productBySku, intval($item->quantity));
   $quoteItem->setCustomPrice($item->price);
   $quoteItem->setOriginalCustomPrice($item->price);
   $quoteItem->setDiscountAmount(5);
   $quoteItem->setTaxAmount(5);
....
}

I'm not interested in verifying totals and others, because I set the totals by myself after the quote is saved and the order is created. This is an order migration script and I would very much like to set the discount amount and tax for each row, but it doesn't work.

I also tried to set the quote item discounts after the quote is saved, but it doesn't work as well.

Can you help me with this?