I've been rendering a raster vegetation model (at 30m resolution) through TileMill with good success. Our specific vegetation model has many attributes associated with each pixel, although there are only thousands of unique pixel values across millions of mapped pixels.
I've been looking into UTFGrids as a good candidate for associating the attribute data with unique pixel values (or majority pixel values at lower zoom values) as tooltips. Because TileMill does not allow creation of tooltips with raster data, I've been messing around with Dane Springmeyer's utf-example-writers and can customize one of these scripts to create UTFGrid tiles of my raster data at zoom levels to correspond to my image tiles.
So two questions:
Is it foolhardy to approach this problem in this manner? I can't see why it wouldn't work but I may be overlooking something.
Assuming I can build a file structure of UTFGrids to represent these raster data, is there any way of incorporating these into my existing MBTiles file? I would guess I could hack it by converting the tile data into sqlite records, but could mbutil be used to integrate the UTFGrid tiles in directly?