If everybody in this situation would copy the certificate (and private key, don't forget that one), it would decrease the load on Let's Encrypt servers somewhat, which is a good thing. If everybody just got duplicate certificates from the Let's Encrypt servers, it would increase load, which is a "bad" thing. (I'm putting "bad" between quotes, because the actual increase in load on the servers is probably very tiny considering the fact Let's Encrypt issues almost two million certs per day, but if the group of people requesting duplicate certs is large enough, it might have a detectable influence. So it's probably more a theoretical/principal issue than really a practical one.)
That said, if you decide to copy over the certificate (which I personally think is a sign of "niceness" to Let's Encrypt considering the load on their servers), don't forget you need to securely copy over the private key corresponding to the certificate. You could use
scp for that, which should be secure. Or encrypt the key in a strong way before transfering it in some other way.
Acme.sh also has the option to re-use the same private key for the certificates, so you would only have to securely transfer the private key once. If you decide not to reuse the same key, you'd have to securely transfer the private key every time the certificate was renewed.