Sorry I made a mistake on the L number...The Royal is L091 and gold Nugget L81.They are mainly a veggie eater but do take bloodworms and other meaty pellets.
If your feeding your Discus beef heart I would not recommend putting one in your tank.
They do eat wood and poop everywhere which is the main problem and will graze on glass and eat any algae when lights are out. So if your up to that extra chore a good bottom vac will be required more often.
If your looking for a nice pleco and compatible in a discus tank...look into the L134 Leopard Frog Pleco. I've had a group of 10 in my tank for 6 yrs. now without issues and only reach 4" to 5" tops.
...Ralph