Another simultaneous interaction that doesn't behave as expected: Having the relic for healing when stepping on red, when you pass by a brute just before stepping on the red, the healing does not trigger - only the damage from the brute.
Not a bug, but an edge case suggestion - make cavalry relic (open chests with blanks) to work on picking crosses in boss fights. It is a marginal improvement, but can save runs ... like mine from today