I stopped doing alternating-character fonts at the end of 2020 when I ran out of ideas. Recently I thought that alternating bottom-heavy letters with top-heavy letters might be interesting. I based the letter shapes on a distorted oval or egg shape, with the stoke narrowing at the narrow end and widening at the wide end. After doing two sets of letters based on the shapes of upper-case letters (A & B), I added two more sets based on lower-case shapes (c & d). These four sets of letters are arranged to form six different fonts, four of which are spaced for alternating character sets (AB, Ad, Bc, & cd). In the picture below, the first two lines are of the two sets of letters that do not alternate, one with the top-heavy characters (Ac) and the second with the bottom-heavy characters (Bd). The other four alternate the four sets of characters.
The result is a typeface family very different from any other that I am aware of. It is available at myfonts.com.