Combine sugar substitute, eggs, cocoa powder, xanthan gum and almond milk in blender and blend until smooth. Pour into microwave safe bowl and microwave on high 1 minute. Stir mixture and microwave 30 seconds; repeat this step until mixture thickens slightly. If lumps form, stir vigorously or run through strainer to remove them. Whisk in 1 1/2 cups heavy whipping cream and salt. Cover mixture tightly and refrigerate overnight or at least 8 hours.
Meanwhile, combine chocolate and remaining 2 tablespoons heavy cream in microwave safe bowl and microwave on high for 30 second increments until melted. Stir to combine; add bacon and stir. Cover baking sheet with wax paper. Spread chocolate mixture over prepared pan and chill until hardened, about 10 minutes. Once hardened, roughly chop and set aside.
When the ice cream mixture is fully chilled, run it through an ice cream maker according to manufacturer’s instructions. During final minute or two, stir in chocolate bacon pieces and toffee. Serve immediately or freeze until firm. If serving out of freezer, defrost ice cream 15 minutes at room temperature before eating.