Dongles can also be handy for peripherals that are frequently used on different machines, particularly if they don't have built-in multi-pairing and quick host switching.

One exception to the "no BT/LE stack" case is the combo of Apple input devices paired with Macs or hackintoshed generic PCs with a handful of Broadcom-based BT chipsets used by Macs. macOS flips some bit on those cards that tells them to keep Apple peripherals paired at all times, which allows you to type and mouse around in the pre-boot environment and subsequently-booted OSes without drivers even on old BIOS-based machines which can't load EFI drivers.