Like others have said, I don't think you will like having the block flying around, could be dangerous depending on the length of your proposed pendant.

Could you remove the cam cleat from the block on the cockpit sole and route the mainsheet up your pedestal (or somewhere you can reach it) to a cam cleat mounted there ?
You would probably need to add a block to route the mainsheet up the pedestal.

Will the block allow you change the angle of the cam cleat upward ? Or turn it upside down ?

A picture would help.

Cheers,
JM.