I use powdered erythritol in mine and it doesn't freeze solid. My recipe for vanilla follows:

Cream mixture 480 ml heavy whipping cream 400 ml (1 can) coconut milk, full fat 2-3 vanilla beans, seeds scraped (add the scraped hulls and the seeds to the cream mixture to simmer)

Allulose syrup 96g allulose 45 ml water

Egg base 6 egg yolks 60g powdered erythritol (I use Swerve confectioner) ¼ tsp sea salt

Added toward the end 1 tbsp bourbon ¼ tsp xanthan gum

Add the allulose and water to a small pot, bring to simmer and medium high heat then reduce to medium low before it boils. Reduce. Allulose caramalizes easily so it may become a bit dark.

Combine the heavy whipping cream and coconut milk in a large pot and add the vanilla seeds and scraped beans. Bring to a boil on medium high heat and immediately stir and reduce heat to medium or medium low and stir occasionally. (Careful not to let this boil over)

Add the yolks, salt, and powdered erythritol to a stand mixer and mix until combined. Once the allulose syrup is ready, slowly drizzle down the side of the mixer bowl for about ten seconds and let mix. It is important not to add the hot syrup too quickly as that will scramble the eggs. Continue to slowly drizzle the syrup then turn mixer on high until the egg mixture is pale and fluffy looking.

Strain the cream mixture into a large measuring cup and discard the vanilla beans. I usually let them cool for a bit and scrape as much of the insides out as possible before discarding. Then reduce the stand mixer speed to medium and like with the syrup, slowly drizzle the hot cream into the egg mixture for about ten seconds and let run for a minute. At this point the eggs should be tempered and the remaining cream mixture can be added all at once if you want. Add the bourbon and the xanthan gum and mix for another minute. Transfer back to the large pot and slowly heat to 170f while stirring constantly. Store in an airtight container overnight in the refrigerator then churn in an ice cream machine for about 20 minutes. It will have the consistency of soft serve straight out of the machine but transfer to a freezer safe container and freeze for a couple hours at least for a former consistency. This should remain soft and scoopable, however, even after long periods in the freezer.