New shrimp!
Sounds exciting.
RCS are very fun and pretty hardy. Sometimes the shipping can be hard on them but since they waited for better weather it should be good.
Already shot out some info on PM but now that you have them and you have this thread. It should go here.
Congrats on the new additions for your tank.
Some info on them in a Edge tank is they are very hard to get out. If you need to get them out. A fishing net about 3" wide is good but I had to custom bend mine so it would catch the shrimp in the weird corners, also had to bend up the handle as well. So I would suggest a not too heavy duty special net.
I got the one Fluval sells for it and it didn't do much for my being able to catch them.
The Gravel vac is good. You should vac well before the shrimp have the babies. Also get a white bucket for pwc. This allows you to see babies if you suck them up in the pwc/vac.
You let the water settle in the bucket then gently swirl the water in a circle. The fry scatter in jerky motions and dart out of the swirl allowing you to see them and you can then net them. Also get a Solo cup with the white color inside. You can take a bunch of debris and check for babies the same way only up close.
Think of how tiny their stomachs are... so very tiny, I was told to think of their stomach like the size of their eye, and to feed that size amount 1-2x per day.
You can always scoop out uneaten food but to me it is better to not have to take that chance.
Also recommend not to use flake food, unless it is super high quality. It can turn to ammonia very fast and as you know poor water quality is bad news.
Hope everything worked out and they are doing great.