There is this thread in the forum, may include your bank [LIST] Banking Apps on /e/OS
You might try
What will happen when you install any custom ROM on a Samsung is that WARRANTY VOID, expected to be seen on the ODIN mode screen, will change from 0 to 1. (Unknown to me but some of the newest generation of Samsung devices feature an Odin mode screen with less information than the original.)
Say after /e/OS install, you decide to revert to a stock ROM it should work fine, but the WARRANTY VOID would remain as 1.
More generally, loosely speaking, Knox is about Remote Monitoring – one would hope that Remote Monitoring would halt after /e/OS install but I am not certain the exact status of Knox after a custom ROM install.