I knew that it was not a pop up.
No issues with water not draining yet. Its in a guest bath so not used that often
This one is not designed for sinks with overflow drain built in. Home Depot does carry a few but make sure you get the correct type as the tall faucets many times do not have a control rod to actuate the drain up and down.
A non-closing drain style is one that has no cover, just holes to allow water to flow down into. Typically there are multiple 3/16" holes in a pattern to allow the water to drain and there is no device or cover provided to stop the water and hold it in the sink.
This is sold as a kit only at the store however you can try the customer service desk to see if they can order the cap from Glacier Bay and have it shipped to the store or your home.
No. Dumb expensive product.
Try your local Ferguson plumbing supply store or any retail plumbing supply. They should be able to provide the gaskets that will work.