We've been doing a lot of cast-in-place pieces recently.
We tried doing some with the cherry resin, and I'm fairly confident that it's not a completely viable solution.
The burnout temperature (as Metalcaster stated) is generally quite a bit lower for cast in place pieces, and at those temperatures, the resin doesn't burn out very well and you get a lot of pitting.
If we're casting diamonds in place, our burnout doesn't go any higher than about 1100 degrees F, with a casting temp of about 900.
For garnets and sapphires, we use a longer burnout at a lower temp (about 950 oF).
There are investments that are specifically designed for casting stones in place though (such as Kerr SatinCast Diamante), and we have some on order, and will definitely see if it's any better. Theoretically it allows slightly better heat protection for the stones, and somehow still allows all the benefits of Satin Cast 20.
And I second the statement about now setting stones too tightly in the wax/resin. You want a minimum amount of material touching the stone, because shrinkage can cause breakage. Also, if the stone is really set/melted into the wax, when the metal fills it, it will completely conform to the facets, causing it to look really weird (basically the metal will reflect light coming in through the top of the stone and will have a gold color instead of a bright diamond color).