Probably the most direct solution is selecting specific servers sets on each machine or different FQDNs on each device.
An automated solution from us is unlikely. Say that you connect to server A with some cert/key pair. Another machine of yours connects to the same server A with a different pair. If we banned the new machine from connecting (either at server level or (even worse) at client level by intrusions on your settings) we would be adding an intrusive feature which is unwanted by many users. Probably unacceptable especially when you consider how easy is avoiding this problem with your own mind.