When I saw this I had to sign-up, so first post!
For what it’s worth here’s my two cents on a Red Velvet wedding cake: I just finished one and although I didn’t use Rose’s recipe (I would have if I’d thought of it at the time!) the one I did use had only veg oil (no butter) and I added 4 Tablespoons of cocoa instead of the usual smaller amount and cut back a bit on the flour. Using all oil may make for a moister cake but I’ll let others with more experience give their opinions. I used the insulated Cake Strips on the larger layers which kept the cake flat and I believe added to a denser, moister crumb.
The food coloring was a “Red Red” - there are many variations on the red coloring theme these days and this one worked really well with the extra cocoa to give a rich red that did not look electric as many low cocoa recipes do.
I also chose to go with a cream cheese icing instead of a fondant because I really believe that is what makes this cake so special in addition to the red color. This was a 4 tier for 250 and it was a huge hit! You have no idea how many people came up to me (I was a guest as well) and thanked me for not using fondant, although it’s slick looking most people find it tastes way too sweet and “plasticky”. The comment from the bride and groom was that this was the first time they had ever seen a whole wedding cake eaten on the spot!
Yes, trying to assemble this cake whole and deliver it would be touchy but I did the final assembly on site and a patch kit took care of any divots!
If you still wanted to go with fondant I would imagine that if the cake was baked properly and well chilled before putting on the fondant, it would not get crumby, but that’s only a guess.