I see at least two other ACME based Free CA services: https://www.buypass.com/ssl/products/acme https://www.buypass.com/ssl/products/acme This one appears full

I see at least two other ACME based Free CA services: https://www.buypass.com/ssl/products/acme https://www.buypass.com/ssl/products/acme This one appears fully drop in compatible with LE, except that it does not offer wildcards. https://zerossl.com/ https://zerossl.com/ Does offer wildcards, but slightly less compatible, because you need to sign up with a web form, and provide your credentials via the optional ACME EAB feature (External Account Binding), so not all tooling will support it.