additionally: while it is to early to say something about the latest iOS/iPadOS releases, iOS/iPadOS <=17 are prone to introduce errors in the exFAT filesystem, wich a.) will prevent to mount the drive on the idevice until b.) it is connected and fixed on a WIN/Mac/Linux machine. There are several threads here on MR related to that.
Besides that: listing folders with a lot of files is faster under APFS compared to exFAT.