eBay Personal Account Managers (PAMs) are starting to support all seller accounts and not just the account that meets thresholds for that particular seller. Some sellers have already received emails from their account manager asking them which other accounts they sell on so that they can offer help and advice.
It’s worth noting that Customer Support probably already know which accounts you trade on, I know when I spoke to my PAM they were amazed at how many eBay accounts I’ve used over the years for different projects. However just in case one has slipped through the net if you’ve got an account with a PAM feel free to talk to them about other selling accounts that you use.
It’s always been bizarre that established sellers can’t get support on other eBay IDs, especially on new selling accounts that don’t yet qualify for account management. Support on other eBay IDs can only be a benefit to sellers enabling them to get personal assistance from their regular eBay contact on all their eBay accounts.