I'm honeslty amazed how well my RDTAs wick, even when I cut the tails 'short'. Some of it due to tipping I'm sure, but I don't do it intentionally. Carrying my vape around, normal movement and the like does a pretty good job I guess.
If I leave my tails too long, they get in the way of filling it and the juice staying level in the tank. No problems, just my OCD.
In all honesty, look closely, even when the juice is well below the ends of the wicks, I can see the juice 'reaching' the bottoms and sides of the tails if they are near the edges of the glass. It's magic capillary action, lol. I just fluff the ends of my tails so they end up being close to the glass, even when they aren't long. I can vape the tank dry and not have issues. I'm sure there is some tipping involved, but I don't do it intentionally.