No I didn’t. I was speaking to domain name validation generally - as in a way for you to prove your ownership and control over a domain name.
Yes, of course DDoS or any kind of traffic can be pointed at an IP or any arbitrarily created DNS record.
The only way for a “reputable” stress testing platform to validate IP space would be RIR validation via WHOIS or similar, PTR records, etc. Of course this isn’t practical because most people don’t control their IP space or even have the foggiest idea what any of that means (because why should they).
Suppose:
DDoSes operate on IPs, not dns names. In the end, the target IP is getting DDoSed anyway.