Hosterion - https://hosterion.com - supports Letsencrypt since many years ago. We even wrote our our cPanel plugin to activate and renew LES SSL, before one was available from cPanel.
Reference:
All web hosting costs benefit from free SSL certificates for all domains hosted. You create your own SSL certificates Let's Encrypt from cPanel, and later on they are renewed automatically, without your intervention. Unlimited web hosting
KnownHost, https://www.knownhost.com supports Let's Encrypt on all platforms and has fully supported it on shared hosting for a while as well as the default choice.
Let's Encrypt certificate is automatically generated once the domain points to our servers, of course we cannot enforce the redirect, that is the client's responsibility since they create their own websites and configure as they please.
If you're controlling the certificates installation, why not the redirect too? Seems to me you have access to the webserver, at least on shared hosting. For services like VPS I assume you don't get certificates too, so I assume we're talking about shared hosting here to begin with?
Usually the redirect is done at the webserver level using the HTTP Location header, not necessarily the "website" level.
So while we create the Let's Encrypt certificate automatically, the client is free to decide not to use it, or to use a paid certificate according to his/her needs.
We could enforce https? Sure. Not only on shared, but also on managed VPS (with our managed VPS we don't give root access, so for the client the level of support and service is the same as a shared hosting). But I personally love freedom, and try to enforce the minimum possible on our clients
At Konet, konet.gr, we have been supporting the use of Let's Encrypt SSL Certificates on all platforms and all hosting plans for at least 5 years now. Moreover, in the Windows Hosting plans we use only the Let's Encrypt certificate unless a client wants to use a purchased one. The link to our KB which refers to the subject can be found here.
PS: The KB article is in Greek but says what i described above.
Recently got a web hosting for customer with https://www.webhostinguk.com they do offer free Letencrypt on all there web hosting plans ..they have listed letsencrypt as a feature offered on : https://www.webhostinguk.com/web-hosting/
You can as Web hosting UK to list of providers.
Do we want to keep that list alive? unlike 2015 nowadays about random Cpanel host will support https and that list is grow out of bound: visiting random ones it looks like some of them are sold to different host and redirected to them or bankrupted and redirected to domain parking page (like https://www.ngagehosting.uk/) unless we really maintain the list and remove dead/sold ones it would look like rusty ad banner on wall of abandoned building