There's currently a check in `TransportService.HandshakeResponse.isIncompatibleBuild` to stop ES with the same Version but different build hashes from joining a cluster. This needs to be relaxed for cloud deployments where Version is not applicable
server/src/main/java/org/elasticsearch/transport/TransportService.java
private final long requestId;
        private final long sentTime = threadPool.relativeTimeInMillis();
        private final String action;
        private final DiscoveryNode node;
        volatile Scheduler.Cancellable cancellable;
        TimeoutHandler(long requestId, DiscoveryNode node, String action) {
            this.requestId = requestId;
            this.node = node;
            this.action = action;
        }
        @Override
        public void run() {
            if (responseHandlers.contains(requestId)) {
                long timeoutTime = threadPool.relativeTimeInMillis();
                timeoutInfoHandlers.put(requestId, new TimeoutInfoHolder(node, action, sentTime, timeoutTime));
                
                final Transport.ResponseContext<? extends TransportResponse> holder = responseHandlers.remove(requestId);
                if (holder != null) {
                    assert holder.action().equals(action);
                    assert holder.connection().getNode().equals(node);
                    holder.handler()
                        .handleException(
                            new ReceiveTimeoutTransportException(
                                holder.connection().getNode(),
                                holder.action(),
                                "request_id [" + requestId + "] timed out after [" + (timeoutTime - sentTime) + "ms]"
                            )
                        );
                } else {