That’s tricky. There are hints in the first scene of TFA where Kylo senses something about Finn, and he even recalls his name afterwards which could imply that Finn had previously shown some sensitivity in his Stormtrooper training which Kylo noticed. Maybe some subtle sound effect could be used when Kylo sees Finn in the village.
In Rey’s vision in TFA she could hear Finn’s voice saying ‘It’s a feeling’ among the other voices.
I haven’t thought about the other films, but I’m sure there could be moments there as well.