I keep false juli corydoras (my favorite) with my sorority of bettas. They ignore each other and the corydoras will even push the bettas out of the way for food. Corycats are armored and well protected - they're not likely to get hurt by bettas (they also have mild poison, but don't worry about that).
You'll likely find feeding challenging. When you feed your corydoras sinking food your bettas will go after it and even learn that a swarm of corydoras means to go down to the bottom and search for food. Your bettas will learn to become bottom feeders. If you feed your corys and bettas separetely you may find your bettas are eating too much.
I now only feed all my fish at once in that tank and they've all learned to feed on the bottom mostly. I feed sinking shrimp pellets (the corydoras seem to love those), on occasion I use a turkey baster and feed everyone frozen brine shrimp, and also on rare occasion I put a broken up algae wafer (which the bettas seem to think is candy, and the corydoras still go bonkers for).
In my sorority tank there are bettas, false julii corydoras, upside down catfish, ghost shrimp, nerite snails, and otocinclus (sucker mouth catfish). They all get a long very peacefully.
I used to also have albino corydoras and they never shoaled with the false juliis. Also I used to have an orange crayfish (CPO) which is a less aggressive small non plant eating species, he also got along with everyone just fine and would defend himself quite well against the bettas who quickly learned to avoid him (snip snip).