Depending on the importance of a loop and environment it has to work in you could consider adding additional transmitters and do for example a mid-of-three selection and control on this one. Or you could add 1 additional transmitter and control the highest or lowest of the two depending on the fail state.

Does anybody have a good assesment tool that can make this selection?

 

In Honeywell TPS HPM, there is a function called "low selector" which can be connected to two transmitters as input, the lowest value will be sent out for other process point/sequences.

HMP