How do you handle strict rate-limiting on stateless edge workers?

I just finished building Inbondz, a serverless API on Cloudflare Workers that extracts pure text from URLs (strips HTML/CSS/JS). Because it's a free endpoint (api.inbondz.com/v1/extract), I had to figure out a way to stop abuse without a traditional server. I ended up using a D1 SQL ledger to track IPs and hard-cap them at 50 requests/day, plus a global 100k limit. For those of you building on the edge, is D1 the most efficient way to handle this, or is there a better way to track daily IP limits without burning through read/write quotas? (If you want to try breaking my current limit logic to see how it responds, the docs and terminal commands are at www.inbondz.com).