Testing Deep of Night Relics/Builds

I find it frustrating when I put a build together with several buffs/debuffs that are not clearly defined in game that I cannot properly “try out” or “test” the build without putting my rank at risk. I wish you could load into essentially a casual deep of night run (even if there are no rewards) just to play for fun or try out a new build. Like a practice mode.. taking it a step further maybe even the circle doesn’t close you just have free time to explore the map and fight anyone you want and can quit without penalty anytime you want.