I am doing a red velvet cake with wh choc cream cheese filling and crumb coat. I plan to cover it in MMF. I really want/need sharp edges. Is this possible?The only time I have been successful with sharper edges is when I used ganache.

Any tips? TIA

Yes it is possible. Many people freeze their cakes for a few minutes before they the fondant.

I always freeze my cakes, then crumbcoat, then apply the fondant. So, should I put the cake back in the freezer for a few mins again AFTER I crumbcoat??

Thanks!

Yes, many people do that. By doing so, you will have a harder base to put your fondant on. Smoothing techniques also helps get sharper edges. There has been times I used ganache and still had rounded tops.

Yes, I think you would re-freeze after crumcoating, then apply the fondant.