If using, prepare the sugar-free simple syrup by combining the powdered monkfruit sweetener and water in a small pan. Stir to combine and heat for 3-4 minutes, until the sweetener dissolves completely. Remove from heat and set aside to cool.
Place the strawberries, lime juice, rum, and one-quarter cup simple syrup (of your choice) into a blender and blend until smooth.
While the blender is still running, add the ice a little at a time until thoroughly combined. Turn blender off and remove lid. Taste and add additional simple syrup, if desired, and blend for another 30 seconds to combine.
To serve, pour into glasses and serve immediately garnished with lime wheels and/or whole strawberries. Enjoy!
Mocktail version: Omit the rum and replace with one-quarter cup water.