I guess it would work, am I correct that they are 10bit and the CR2 files would be more?
No, this is absolutely not correct. CHDK raw is the same bit depth as the actual sensor data. On the G11, this is 12 bit. For all practical purposes, the data in a CHDK raw or DNG should be the same as Canon raw, aside from minor differences in how bad pixels are handled.
The difference is in how the data is packaged and what metadata comes with it.
In general Canon raw with will probably give you better results out of the box, because software that supports it will be able to output exactly as Canon intended. With CHDK DNG, the color and lens correction may need to be tuned in your workflow.