Srilermorna and Mando'a have been added!
Note, while Mando'a is yet another general reduplication of the Roman alphabet and has exact corresponding letters, Srilermorna is much more complicated and challenging and has its own set of quirks and rules you have to follow to make it not glitch out. These are included in the add-on which should be visible as "INSTRUCTIONS FOR USE"; read that before you use it.
Next on my list: Hylean, Zbalermorna, Dragontongue script. I've also been experimenting with an ambitious jaunt at Hanzi (Chinese characters) but don't expect that any time soon.