Whenever you DISC out anything, you run a risk of missing something.
You can modify those patterns to suit anything that you want. Once you get some practice in, and learn the approximate TIDs of desireable targets, or undesireable targets that you may be plagued with, dialing in custom patterns is a snap.
Also, if you're hunting low trash areas, and especially if you are more interested in relics and coins than gold, then I would suggest that you entertain the thought of a 3kHz coil. The only downside to me of the 3kHz coil, is that they don't have a DD version.....yet. The LF coil punches deeper in mild soil conditions than I'd have believed after using both the 10.5" HF DD and two different 7.5kHz coils. I'm having a hard time bringing myself to take it off.