Is there a way to disable ECMP?
Yes I am aware I can change costs but its just yet another administrative overhead, i'd rather just disable ECMP as we don't need it anywhere in our network
It's not a question of predictable route, it's a question of same path characteristics for every packet. If delay on one path is 10ms, while on another is 30ms, then sending packets by two paths can introduce many issues. So, let it randomly choose 30ms path but ALL packets will arrive to destination ordered with the same delay (well, I'm not talking about fluctuations).Even if you somehow disable ECMP, you will still have "unpredictable routing".
Only instead of having ECMP routes, which at least are easily seen in the routing table, you can end up with asymmetric routes.