Time for an update.
Despite endless promises and sending the merchandise back to the vendor, I have no replacement flashes. So: do not buy stuff from Meking Studio on eBay, they're liars and swindlers.
Secondly: PayPal denied my refund claim. They gave me no opportunity to present evidence that the items were received DOA but accepted an "explanation" from the seller and found in their favour. They don't tell me what that explanation is or provide any reasoning for their finding.
So, fuck you PayPal, your Buyer Protection is absolutely worthless. I am now out about $800 for shitty merchandise and a lie of a "consumer protection" scam.