The least amount of connections possible is generally the safest rigging system. Thimbles like this add another failure point to the system which seems a bit of a step backwards.
A note on needing a shackle. I think whatever device you need to connect to your rigging system should be on the winch full time. This is one place a hook generally excels. I was on a trip last season where a rig came VERY close to rolling over forward. It was only quick thinking using the winch on the trailing vehicle as a tether that kept him safe enough for a full recovery. I was able to hit the disconnect on the winch, pull just out enough line to hook the rear of the vehicle, engage the winch, and then have the driver put tension on the line by backing up slightly. This was all done without having to wait for anyone to dig out a shackle, use a tool to loosen a shackle, or find the winch controller. I'm in the camp where the less you need to dig out the better, especially if it involves opening doors, digging out gear, undoing cargo straps, etc.