I know it doesn't crust but does it set firm after refridgeration? I want to add fondant accents but I don't think I can if it stays completly soft??

If they accents are not too heavy, they will stick to the buttercream.

SMBC will harden because of the butter content. But it will soften up again when it returns to room temperature.

HTH

Thanks guys! I have just made up a load and love the texture! Will stick fondant on later