でも、Let's Encryptさん（certbotさん）レートリミットあるからあんまり頻繁にやり直さないほうがいいかもわよね
Rate Limits - Let's Encrypt - Free SSL/TLS Certificates https://letsencrypt.org/docs/rate-limits/
letsencrypt.orgRate Limits - Let's EncryptLet’s Encrypt provides rate limits to ensure fair usage by as many people as possible. We believe these rate limits are high enough to work for most people by default. We’ve also designed them so renewing a certificate almost never hits a rate limit, and so that large organizations can gradually increase the number of certificates they can issue without requiring intervention from Let’s Encrypt.
If you’re actively developing or testing a Let’s Encrypt client, please utilize our staging environment instead of the production API.