You can connect Other World Computing's "Thunderbolt 4 Hub (Thunderbolt, 1 port)" to your iMac 24" M1, but there are a few considerations to take into account:

- The hub has multiple ports, including four Thunderbolt 4 ports and one USB-A 3.0 port, so you can connect multiple devices.
- You can connect up to three external hard drives via the Thunderbolt 4 ports or the USB-A 3.0 port, depending on the needs and connection types of your hard drives.
- Make sure that the external hard drives are compatible with the ports available on the hub and that you have the appropriate cables.

In short, yes, you can plug this hub into your iMac 24" M1 and connect several external hard drives to it.