Re: It’s a Geo orbit
I think they have achieved this a few times (and tried but failed a few times) but, yes, the first stage comes back virtually empty and much faster than ideal. And, yes, there is a cargo weight limit where it just can't be done.
According to wikipedia: JCSAT-14, Thaicom 8 and SES-10 all had successful (but hot/fast) landings but EchoStar 23, for example, was too big.