To answer your question: I don’t think this is currently possible. Even if you exclude the machines, the servers will still join the cluster (exclude simply means that they won’t get any roles assigned).
However, this looks concerning to me:
This might be clear to you, but I still want to point this out here: if people (I assume this means developers) can accidentally join your production cluster, you probably have a huge security issue. A developer shouldn’t be able to join a production cluster at all (not with a server and not with a client).
Imagine a developer assumes she is working on a local fdb instance and executes the following command:
fdbcli --exec 'clearrange \x00 \xff'
Now your production db is gone!
When working with FDB you should never rely on FDB for security. You should always keep production and development in different environments (by using firewall rules and VPN).
For development you probably don’t want a shared fdb cluster. Instead each dev should have a local fdb installation.