Update: Thought I would share the details for people who have not gone through the process before....
Listed my Dynadot domains on GD Auctions yesterday at around 1pm UK time got auto responses saying "Congratulations, you successfully submitted......."
very soon afterwards got multiple emails for each domain listed
"You have recently requested for the following domains to be listed for sale at GoDaddy Auctions:
In order to authorize the auction for these domains, please update the DNS record for each domain with the provided TXT record. To find the TXT record:
1. Log in to your account.
2. Click on your settings tab
3. Once in settings navigate to the Domain Ownership Verification section to view your personal TXT record
This TXT record is yours alone and will work for all domains you wish to have listed at GoDaddy Auctions.
To update your DNS please contact the Registrar where you currently have your domain(s) registered. Once you have added the record to each domain(s) DNS please reply to this email and we will re-attempt verification. "
Headed over to Dynadot bulk updated my txt records (very easy process)
Replied back to one of the emails saying I had updated all txt records from yesterday and got an email back a couple of hours later saying they where on GD Auctions - checked and they are live
Very simple process, pretty quick apart from the listing category part
Only reason it took so long is because I did not update the txt records straight away as I had things to do...though 24 hours is not a huge amount of time....