Upon a closer look, it indeed seems that the certificate count limitations apply to the manually requisitioned certificates, not the ACME ones: > By using Zero

Upon a closer look, it indeed seems that the certificate count limitations apply to the manually requisitioned certificates, not the ACME ones: > By using ZeroSSL's ACME feature, you will be able to generate an unlimited amount of 90-day SSL certificates at no charge, also supporting multi-domain certificates and wildcards. Each certificate you create will be stored in your ZeroSSL account. So I guess that's a viable option.