Tiramisu thickening tips & tricks?

I like making tiramisu with meringue instead of whipped cream just to not waste egg whites, my family and I personally like the looser, custard texture it has compared to the fluffy, cake-esque texture whipped cream has, though a lot of my friends are very used to the cream version, so I've been trying to hit a middle ground.

I make the cream with a zabaglione and italian meringue, both for thickening and for the sake of having no raw eggs in the tiramisu, though the result is still on the looser, custard side. Anyone have any ideas on additives (does xanthan gum work?) or extra techniques that could help this recipe hold shape a little better?