I was investigating this issue and found both the old Plurality example included with the extension, as well as the new example in the Inform 7 documentation entitled #249 Olfactory Settings. By comparing and contrasting these two examples, I was able to do the conversions I needed.
I’m posting both examples here because others might find them helpful as well.
Here’s the old Plurality extension example:
The Doghouse is a room. "Not so much a place as a state of being."
The player carries a ticket to the opera, some papers, and a bouquet of flowers. The bouquet is ambiguously plural.
Instead of eating something inedible, say “[The noun] do[es]n’t seem likely to agree with you at all. You’d be wiser to leave [it-them] alone.”
Instead of touching something: say “[That-those of noun] [is-are] all prickly.”
Instead of smelling something: say “Your nose is too weak to get much smell from [that-those of noun].”
Instead of smelling the bouquet: say “[It-they of the noun]['s-'re] lovely.”
Instead of tasting something: say “Whew! [Is-are of the noun] [that-those] ever nasty!”
Test me with “x ticket / eat it / eat them / touch it / touch them / smell it / smell them / taste it / taste them / x papers / eat it / eat them / touch them / smell them / taste them / x bouquet / eat it / eat them / touch them / smell them / taste them”.
And here is the new Inform 7 example:
The Doghouse is a room. "Not so much a place as a state of being."
The player carries a ticket to the opera, some papers, and a bouquet of flowers. The bouquet is ambiguously plural.
Instead of eating something inedible, say “[The noun] [don’t] seem likely to agree with [us] at all. [We][’]d be wiser to leave [regarding the noun][them] alone.”
Instead of touching something: say “[regarding the noun][Those] [are] all prickly.”
Instead of smelling something: say “[Our] nose [regarding nothing][are] too weak to get much smell from [regarding the noun][those].”
Instead of smelling the bouquet: say “[regarding the noun][They]['re] lovely.”
Instead of tasting something:
say “Whew, [regarding the noun][are] [those] ever nasty!”
Test me with “x ticket / eat it / eat them / touch it / touch them / smell it / smell them / taste it / taste them / x papers / eat it / eat them / touch them / smell them / taste them / x bouquet / eat it / eat them / touch them / smell them / taste them”.