Developers prefer to try before they buy, therefore easy self on-boarding is an important part of good DX. On occasion, developers may hit a blocker and wish to speak to a support person. Don't make them work hard to find your support forum. If you do, the developer may end up contacting sales which can be both frustrating and counter productive for both parties.
Keep in mind that SDKs will influence the types of questions your support team receives. Code libraries, documentation, guides and code samples provide developers a self service onboarding option.
Your support team will spend less time answering questions about authentication and more helping developers solve their unique business problems. If developers run into problems using your SDK, the support team can recreate the issue using your SDK and propose a fix or submit a bug report to your engineering team.
From experience, having SDKs increases the effectiveness of support teams and allows you to support more developers with a smaller team.