My yoyo waits until the rest of the tank members have taken their share, then goes up around the filter and powerhead crevices and eats what has collected there. The angelicus don't wait, though; they zip right up to the top and eat with everyone else.
Do your frozen bloodworms thaw a bit and then drop off into the water? Will the angelicus eat them if they float down some?
Also, try sinking veggie discs for them. Mine were clicking away on one this morning.