Nova launcher probably is the best but not for the fold. Stock is best option for the fold but you need a third party app by Samsung called goodlock to make it decent. For some reason Samsung can't just put the features of goodlock in the launcher. Most people that don't explore the forums don't know about goodlock. I also like using the task bar on bottom screen now and that only works with stock launcher.
Niagra launcher works good on the fold, developer designs it to work with the fold, and large screens, but it's a basic launcher. Forget about widgets which is why I don't use it anymore, but it does work good.
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