RE: Swiss Meringue Buttercream

I’ve made smbc many times. And yes, you can put smbc under fondant/sugarpaste. Just make sure cake is well chilled before covering with fondant, as smbc tends to be soft. Smbc doesn’t really harden/crust like regular buttercream. And you can add lemon flavouring to the icing, or any flavouring without issues. As for chocolate, I just added cocoa powder to my smbc. Here’s the recipe I use. https://sugargeekshow.com/recipe/swiss-meringue-buttercream/
Now I don’t make smbc anymore. Although I love it, my family doesn’t. And didn’t want all the fuss. So now I make a “mock” buttercream with pasteurized egg whites. Tastes just as good, actually better to me, like vanilla ice cream. Here’s the recipe I use. https://sugargeekshow.com/recipe/swiss-meringue-buttercream/
Try making both and see what you think. Which one you like.