A set of letters and numbers, but with the connecting brick types swapped would be useful to make a checkered look for words, especially if they contain one- and three-wide letters, such as I, M, W, etc.

Possibly define them in other blocks (such as the PUA, which is used without conflicting with Unicode Consortium assignments).

I do this for glyphs with don't have a Unicode codepoint, such as small caps and localized forms. I usually start placing them with U+E000.

Befoure you ask about the small caps, yes, I am aware that small cap letters exist in Unicode, but those are usually for phonetic purposes and should not be used for small cap text…

Cliff