This was never supported in vRA 7 so I doubt it's possible in 8.
If you want to use friendly name I would recommend to use some load balancer like NSX (Record A with friendly name point to LB and LB redirect users to correct URL). vRA supports also F5 and Netscaler.
Probably you can use some open source LB like HAproxy but remember that it is not supported.
In vRA 7 record A in DNS is not sufficient because you need to point A record to long url (https://<vra>/vcac/org/<tenant>
I don't know how vRA 8 works but I suppose that there is the same problem.
Ok, I've read once again what you did and I've checked that in vRA8 url is just simple hostname.
1) You have record A and PTR that correspond with you hostname for example vra.your.domain
2) Create CNAME (not record A) with friendly name for example: cloud.you.domain and point to record A vra.your.domain
Of course friendly name should be included in SAN (Subject Alternative Name).
Check and give me a feedback I am curious.
I also did some test using a cname but its gives the same error "404".
I guess its should work using any kind of load balancer but it will be a little over kill in my business case since its a small deployment with only one server.
Sadly they havent thought of that. So it is currently not possible, unless you deploy it HA, because there you need a load balancer.
It worked in vRA 7 like a charm and was also our best practice if you went with a single deployment, so you could scale out afterwards to an HA deployment.
Please create a feature request to help to raise the awareness on the VMware side.
TBH they have thought of that, but let's say there are some technical challenges to it ...
Using LB is the option at the moment.