Shareable early-access discount code restricted to email list

Merchant wants a single shareable discount code to send to an email list for early access, with the code only usable by that recipient group (manual entry by customers). This requires support for customer targeting (email/list restriction) and potentially usage limits or one-time-use per recipient—features not currently supported. Suggested feature: allow creation of advanced discount codes that can be restricted to specific customer emails or segments and optionally set per-customer usage limits or single-use tokens for early-access campaigns.