Generally I consider a layer cake to be composed of two 1”-2” high cakes (so this usually means baking two cakes of the same size and then putting a filling/frosting between them for a total cake height of 2.5” - 4”). A tiered cake is one like a wedding cake where multiple layer cakes are stacked atop one another. In the book, I understand 1 layer to mean one cake—I believe Rose is very specific regarding this—for some recipes it will make 1 - 2” high layer (as in the Chocolate Domingo) and with other recipes she will specify that the recipe makes 2 - 1.5” high cakes such as the chocolate butter cake. Of course, in her wedding cake section she uses different charts, but in the end, they all should have the same formula as the “sister” recipe in the earlier part of the book. So, I’m not sure I fully understand what you want. If I was making a stacked (2 -tier) cake—I would bake 2 - 10” round (by 2” high) layers and then 2 - 8” (by 2” high) layers. This would give you (roughly) 4” high tiers (for a total cake height of 8”).
If you are using the chart on P.502, using the 8” rose factor of 7 will make two 8"round by 2” high cakes. To get the amount for 2 -8” round cakes, multiply the base formula on P. 504 by 7 (if you only want 1-8” cake, you will multiply by 3.5 instead).
Similarly, for the 10” layers, you will need to multiply the base formula for genoise on P. 504 by 11 (if you only want 1 cake instead of 2, then multiply by 5.5).
If all you want is 1 -10” cake (by about 2” high) layered with 1 - 8” (by 2” high) cake, then I think the fruit cloud cream would be fine, but if it is a stacked cake (totalling 4 cake layers) then I think I’d avoid the fruit cloud cream.
I hope this helps.