Just trolled back through a few months and found two SS Pacers races at Menangle 26/6 and 20/8 (There may be a few others in there )
At these meetings the SS on Breeders day held $45K in the win- The highest win hold of the day. This may be for several reasons EG/ later in the day (was r8 of 9), Karloo Mick was in it.

The SS on the 20/8 held 39K in the win, the 3rd biggest win hold of the night. Again, it needs to be taken into account that it was race 1 that night so would of got a spillover from those punting on the gallops that day.
I realise it will be a different kettle of fish turnover wise running stands at Penrith, but positioned early in the card, they might hold commensurate with what they would for some of those mobile races dominated by an odds on fav...At least with the SS, as GMac says, there may be some false favourites and less likelyhood of one horse stifling the market......
Can only give it a go and see how the participants feel via noms and punters via turnover.....