Yes, I did— or at least substantially. This is the norm in electronics manufacture, thats what investors are for, normally you don't have the customers funds before your design is done and manufactured. Pre-orders are unusual. Even in custom one off manufacture in the commercial market not only is payment normally provided _at delivery_ but goods are often invoiced net-30, so you won't get paid until sometime after delivery of the product.

Besides, you can factor out the exchange rate noise, just assume that the exchange rate was constant. In (some/most/all) states you are legally obligated to provide full refunds for pre-orders with fairly short notice on late delivery, and— obviously— in all states you are required to refund customers if you don't ship a product.  So they wouldn't have been able to meet even the most conventional of obligations, in the worst case (e.g. their design failed) if they'd been spending the pre-order funds to fund design and manufacturing.

In the mining space pre-order lets a maker lock in outsized prices and deny business to the competition by locking up the customers funds early. It might also be used to fund development and manufacture but if so, thats very risky, and may create all kind of adverse exposure for the business. Better to get investors with clearly established rights and obligations.