I know I only bother with these more annoying products after I've already tried and failed with the alternatives. Its not so much the few minutes dealing with registration and the other time working out if access to the private repositories are going to be a hassle with my environment and security policies, its the first sign that you are dealing with a company that is going to be a hassle.
So please leave up the registration forms, because it signals to me that I will be dealing aggressive sales departments, fine print and hidden expenses. And I'm only going to do that when I've exhausted my alternatives. Maybe it isn't true, but its what I've come to believe over the last few decades, and I'm not the loser in this scenario since I just investigate the easier to deal with solutions first. And not much point continuing if I find something good enough and free, which is why I'm currently migrating my old DSE clusters to new hardware and Apache Cassandra 3.11 despite my poor experiences with older versions (I was pleasantly surprised with 3.11 and look forward to seeing 4.0).
Also Scylla provides non-gated access for AWS users with ready-to-consume AMIs