Vertica SAAS offering in Azure Marketplace

We recently completed a test of the Vertica SAAS offering in the Azure Marketplace. We know that one-size doesn't always fit all, so we are not going to use it at this time. What would be the best way to communicate the issues that dissuaded us from using it to Vertica so that if they decided to improve the offering they'd have real life feedback on it? Support ticket with any special option? thanks!