Flexible API Pricing Tiers with Stripe? Seeking Solutions!

Hey Product Hunt! 👋 I'm setting up a usage-based pricing model for our Partner API. First time Stripe user here, and I’m facing some challenges with Stripe's functionality. Here’s the setup I’m aiming for: Each pricing tier has a set number of API calls included per month (e.g., $50 for 1,000 calls). Ideally, if a customer goes slightly over their limit (say they use 1,010 calls), they’d pay a per-call overage fee (e.g., $0.15 per extra call) instead of having to upgrade to the next tier. Here are the main issues I’ve run into: Manual Tier Selection Without Forced Upgrades: I want customers to pick their preferred tier at sign-up without being forced to upgrade automatically. For example, if they’re on Tier 1 (1,000 calls) but use a few extra calls, they’d just pay the overage fee without needing to upgrade to Tier 2. Metered Billing Limitations: Stripe’s metered billing helps with overage charges, but it doesn’t seem to allow customers to start at a higher tier without automatic upgrades. For our larger customers, I’d like them to pick a higher tier upfront if needed and still have the flexibility of paying for additional usage without switching tiers. Has anyone implemented this type of pricing model with Stripe or another PPS? I'd love to hear any tips, workarounds, or suggestions. This is my first time setting up Stripe, so I may be missing something in the documentation, and I'd really appreciate insights from anyone experienced with flexible API pricing. Thanks in advance for your help! 🙏