Could it be possible to thwart secret chains by forbidding consecutive block verifications by a single mining address or something more complex?
No, that is not possible. Every such a mean can be easily circumvented. Especially if you can make use of virtually every single participating miner's PC. Centralization of mining pools which gain a slight advantage in terms of latency is something we need to prevent. I think the best method right now is just to educate the miners how potentially dangerous such centralization is.