That is my understanding as well - pretty much all multifidas in cultivation are a single clone. You'd have to get pollen from another binata-complex plant. I recently got ahold of some seed-grown location data plants but they're a bit small yet.
You could if you don't want to see the flowers; just cut the stalk and lay it on moist soil like any other part of the plant.
Mind you, if you wanted to cross extrema with another multifida form that should be possible; there are multiple multifida lineages (including white and pink-flowered clones) and multiple locales out there. Whether or not the resulting seedlings would be fertile or not though I couldn't say; the group is a mess.
I was responsible for distributing plants grown from seed collected at Evan's Head NSW. I was also responsible for mislabeling them as regular multifida. These are in fact the D. multifida "extrema" form (not a cultivar), just of wild parentage from that locale. I hope these plants provide genetic diversity to the US gene pool.
I currently have 3 seedlings sundew binata from different sources, but the simple "T". I will try pollinated when possible. managing to send to you to make pollination. as binata multifida, this only have one source and will not be able to send seeds. Planting the stem (base of the flowers) but there is no way to send seedlings.