That Five Star may burn a roast but is it designed to completely consume body parts?
I fully agree with you that ovens and incinerators can be repurposed to multiple uses. Prolific French serial killers Henri Landru and Marcel Petiot used, respectively, a kitchen oven and a heating furnace to dispose of their victims. The old fashioned coal oven is still superior to the Five Star in that it was built to withstand higher temperatures. Landru cooked his meals in the oven between body burns, but I suspect he ate out a lot.
Presumably they also burned household wastes in the oven and furnace (I do in the wood fired oven at my cottage, but no animal matter). Landru and Petiot were both charming and well liked, maybe trained cooks too, being as they had a French background. Landru was quite the ladies man, to the misfortune of the ladies.
Anyway I don't think LE hauled away DM's incinerator because some discovery or tip made them think they would only find charcoal and racoon teeth in the residual, or that they did it to prejudice the public. And apparently LE still have custody of it, maybe because it did contain pertinent evidence? Otherwise I expect that it would have been released, and wouldn't it have been up for sale on Kijiji by now?
Yes, testimony about the incinerator will likely be interesting, if it becomes necessary.