I would like to encrypt movie files that are > 1GB in size. Can cryptomator handle this? if so do I need to adjust any settings to have it run reliably?
Cryptomator does not have any file limits. Neither size nor amount.
But if you use WebDAV as virtual file system (which is not recommended), then you will underly the restriction of Windows that allows only files up to 4 GB via WebDAV.
Or in short: as long as you are using the recommended WinFSP as virtual file system for your vaults, then the only limit is your HD space.
WinSFP will be installed automatically as long as you do not deselect it during cryptomator installation.