Curious other people's setting and logic for inactivity closure lengths

We use Fin’s inactivity auto close feature, initially this was set to a short 15 minutes but due to the nature of our clients industry it would not be uncommon for them to be away from the PC for 45 minutes or so. Last year the setting was changed to 3 hours and since then we’ve noticed our CSAT response rate has dwindled to a meagre 5%. I hypothesise this is largely due to the lengthy inactivity setting and customers then failing to interact and the interaction itself being largely forgotten. I’m curious other users inactivity setting and the CSAT response rate you receive.