This chick could not stand up or walk very well when the toes were curled. To move around it did what I can only describe as an "army crawl" because the toes were stuck curled up. I was about to splint its feet with cardboard and bandaids, but when I went back to the incubator they already started straightening out. So, I let him be. By the next day he was fine. You probably aren't hurting your chick by splinting her feet, as long as they aren't wrapped too tightly. You might want to spend some quality time with the bird to ensure that your treatment is helping, not hurting.
I googled how to help splayed legs and found this:
https://104homestead.com/fixing-spraddle-leg-drinking-glass/
I've found that offering vitamins/electrolytes has given my chicks a very good start, and it looks like
@Mylied thinks they may help, too. It might just give the chick enough of an extra boost to really benefit from any treatment/PT you give it.