Figuring out whether a vendor will care about their customers in a given situation has a very simple, very universal "worst-case rule": if you're paying the vendor, and your "account" (in the financial sense) is typewise-indistinguishable from other accounts, of customers who pay the vendor ridiculously-huge amounts of money, then there will be a good support process for you.

Why? Because big-spender enterprise customers demand that vendors implement hand-holding red-carpet VIP support for them; and most of that work is, surprisingly enough, a capital cost, not an operational expense; and so you can free-ride on it as long as it's been set up.

On the other hand, if there is any way to typewise-differentiate you from the big-spender customers, then you'd better believe that they'll have support channels you don't have.