I do not believe that your goal is in any way incompatible with the IR.
However, I, too, feel that voice vote is going to be your best way forward.
This is much easier with the message search feature: you simply make one person (usually, but not necessarily, the Judge) responsible for tallying the votes for every referendum, then you give each referendum a specific title, and require that every official vote cast must follow a specific format, such as
Official Vote: Alliance with Keplerstan
I vote "Yes".
The "Official Vote: Alliance with Keplerstan" line can be copied & pasted so there can be no confusion; then, once the referendum has concluded, the Judge (or whoever) can use the Message Search feature to find all messages containing that tag, and tally up the votes.
(This is slightly different from Riombara's system; however, it is less prone to breakage, particularly with large groups.)
