Hoist safety

I got a hoist that lifts things via a wire rope. I have no safety issues lifting and lowering items because I can stay out of the way so if the hoist gives then it is a damage issue not a safety one.
However, once the item is hanging, I need to work under it. This is a safety concern. What I would like is to put in a mechanical inline wire rope clamp which could be opened during hoist operation and locked once the item is lifted. That way I would have a mechanical fix on the wire and hoist would just serve as a backup. The challenge is that for various reasons the clamp needs to be opened and closed easily, preferably with a one-handed operation (best if it involves pulling a lever). Does anyone make lever operated wire rope clamps?
The loads in question are small : 150 to 400 lb so this is why I think a simple inline clamp would work especially with hoist (rated at 1100 lb) as a backup.