Polydatctyly (extra toes) is not all that uncommon in cats. As far as I know it doesn't lead to any notable negative outcomes. We had a poly cat (named Poly because that's what the shelter called her) who lived a long and healthy life. Earnest Hemmingway famously kept and bred polydactyl cats at his home in Key West, and if you go visit the staff there still take care of their descendants.

Here's our Poly:

[–] TheOakTree@lemm.ee 4 points 3 days ago

I saw the Polys at Hemingway House, they all look very normal in comparison to Stomp's big feet.

Almost all of them were taking naps in plants and under benches