Well the thing is my betas are friggin pigs. One of them even eats the algae pellets once in a while. I doubt i'd be able to sneak meaty stuff past em :P. So the algae stuff is OK? the first ingredient is fish meal.
don't know if fish meal is first but yeah algae waifer are all good for them.
the other option in just buy betta flakes and feed your betta like normal the flakes that are left over will be eaten by the shrimp.
Feed the shrimp right before you go to bed, hopefully about 2-3 hours after you have turned the lights off in your aquarium. With any luck your betta will be "asleep" by then. Shrimp are active 24 hours a day and are often more active during the night then day, so they won't have a problem with this.