Switch, plug, detachable direction pad?
Make and model keyboard?
Is it possible for you to take a couple of photographs and post the photographs here via imgur (www.imgur.com)?
That said, why not simply cover the open port with a small piece of masking tape?
Tape could work, But I'm looking for something to put in the switch socket that also makes it flush to the board.
I don't need it for my current board (since its budget) its for future project since I'm looking at those split keyboard for myself but since they do not come in the same layout as a full sized keyboard. (I could just by one of those full size membrane ergo keyboards and get close to what I want but no) and some of those have keys in strange places that I don't want/will use. So that why I asking about if there is a plug for that.
Ill throw in a visual example (image i found on google)
View: https://imgur.com/WEyUx8V
If I got this type of keyboard, I wouldn't want the keys I've crossed out and would want something in the socket to make it flush with the plastic.
I know i could use a program to disable those keys but I don't want them on the board itself .
Effectively im hunting for a hotswap ero/split board that around the size of a mini BUT has all the F keys at the top