How are Franson Interferometers used to prove security in Photonic QKD Experiments?

I am currently reading this paper about Quantum Key Distribution Protocols which use Franson Interferometers to secure against eavesdroppers. I am having trouble understanding how the interferometers implement the CHSH game in order to show the correlation between the photons in the experiment has not been tampered with.

I do not come from an experimentalist background and understanding the workings of the Franson interferometer vs other interferometers is proving difficult. I know that in the CHSH game both parties (Alice and Bob) will choose between two measurements to maximize the violation of Bells Inequality. With Franson interferometers what is the analog for these measurements? Is it just the counts of how many photons choose the long branch vs the short? I know some experiments use phase differences in the branch paths and Alice and Bob choose their own phase delays. Does this not destroy the temporal correlation between the two photons?

I know this is a long slew of questions so any help is greatly appreciated!