SSL for custom domains in SAAS

I’ve build a SAAS platform and developed a feature for my clients to use their own custom domains. Currently I am generating Let’s Encrypt SSL certificates by using CW api when a new custom domain registered.
The problem is CW can only support 1 SSL certificate per app and Let’s Encrypt certs max out at 100 domains per certificate. When I search at google, I found below solutions:

I wonder if anyone here has any better solution or have you worked with one of above solutions?

Best regards,