I haven't had a problem using the chi ebi WHEN I had baby shrimps but not got back to that stage yet (I am still using it a bit even with no babbies) as we are approaching the end of winter! I'm not sure how you get clumps of it if it's a powder, I use a tooth pick (or similar) dipped about 5mm into tank water, quickly dip it into the powder, knock excess off and then swirl it round the tank.
Now I do have assassin snails in the tanks as well so they may get any bits that the shrimp don't!
I haven't used the glasgarten myself, though I had it on my 'to try' list, but as long as you don't use too much! It is more difficult though the larger the tank, as the shrimplets need to find the food and don't move far when very young.
I wanted to try bee pollen but haven't yet got back to that point yet and I haven't found it easy to get here? I would imagine the spiulina would be fine, I use that to feed daphnia when I have them, but again I use the same way of adding it to the tank.
There may be no need for additional food though if you have plenty of biofilm as that must be what they naturally eat so lots of leaves are a good platform for that and you are already using the bacter ae!
Simon