While rEFInd is a popular alternative, Clover is often preferred for the Steam Deck because:
Once Windows is up and running, it's time to install the bootloader. The easiest method is using the community-maintained script by ryanrudolfoba (often integrated into larger tools). steamdeck clover dualboot
The standard community method is to use the script or a manual installation via a Windows USB created with Rufus. While rEFInd is a popular alternative, Clover is