I think the idea behind Let's Encrypt was that no-one would need to be without certificate and therefore they donate the certificates. However LE is not that easy to implement, and some would still go without valid certificate to save money. That must have been also the reason why LC supports it, to make it easier to implement.
I wonder therefore why Let's Encrypt certificate management is not available in Basic license and that you have to spend some 7€/month more for Standard license, bringing it again out of reach for many users. In comparison for the price difference of €84 per year you can have either an extensive certificate or you can buy a longer validity. Also the disappointment effect of discovering that LC supports it but then seeing the price that is needed.
That is contrary to the idea of LE. Could you please reconsider this matter? In line with the reasoning to make certificates easy and available for all, wouldn't it be more logical to make it available in all LC licenses? It might give you even a boost in sales when you can market Basic as the most affordable control panel supporting Let's Encrypt!