I tried to program two different discretionary ligatures for same letter combination in FontForge and it didn't work. To clarify I wanted to see if it would be possible to have two different ligatures available for W_E. When I tried to access the second discretionary ligature in Creative Cloud I was unable. I couldn't even make it display by selecting it in the glyphs panel. I could be totally wrong here but it appears to me that the OpenType functionality of discretionary ligatures does not support multiple substitutions for the same letter combination. If I am wrong perhaps this is more of a software discussion.
The typeface I'm creating has many possibilities for ligature combinations of the same two letters. Many of these combinations can also be achieved through combining alternate characters but some ligatures are one solid, combined glyph (See E_D in screenshot below).
Should I just create unicode slots for the additional ligatures and expect users to access them through the Glyphs panel?
This typeface is a display face — uppercase only. So lowercase unicode slots are naturally filled with uppercase characters. What are people's thoughts on setting one ligature for upper case combos and another for lowercase combos? Would this be confusing and produce unexpected results for the user? I've seen other designers set alternate characters in the uppercase unicode slots and default characters in the lowercase slots for display faces. This seems like dangerous territory, especially if someone is passed the font file without instructions. Thoughts on this?
In my opinion all of the ligatures in my typeface are decorative and belong only as discretionary.
Here is a screenshot of some of the alternates and ligatures I've been developing for good measure: