I always do this in Photoshop because Manifold has not thought it through.
Respectfully disagree. There's a difference between thinking it through and deciding to implement what the thinking through leads to.
Photoshop does nothing but rasters. It's totally useless for vector work, for example. It also does absolutely nothing with attributes or spatial context. And it is absolutely terrible at big rasters. That's OK, because Photoshop aims just at smaller rasters, as encountered in photo work, thinking through all that matters for those, and implementing what the thinking through leads to.
Manifold has also thought through what a full articulation of raster capabilities means. That's why the internal infrastructure is what it is. But Manifold has not yet implemented what all that thinking through leads to. Instead, only the bare minimum of capabilities are there, and at that only those which fit in a lowest common denominator orthogonal set of controls related to channels and ranges, have been implemented.
Raster manipulation is easy stuff with very well known and published approaches to things like shading, so there's no reason why, once it bubbles up in priority to the level of being implemented, there could not be a wide range of point and click (not SQL) controls that automate and otherwise provide conveniences for a wide range of facilities for things like blending, shading, etc.
I expect that naturally will gain priority, as the new, low price of 9 is already starting to transform the user base into a constituency with broader interests in presentation, and point and click raster manipulation as in Photoshop. That's a different set of priorities than the more data-centric, spatial ETL orientation surrounding a hard core, SQL oriented, data engineering tool selling for higher price. You never see FME users talking about blending or shading modes, for example.
There's also the steady determination at Manifold that anything possible in 8 would be available, and better, in 9. I always enjoyed the many raster editing tools in 8, with some things actually easier and better than in Photoshop, so it will be nice to have analogs in 9, but analogs not held back by the limitations in 8. Doing texture shading on the fly in 8 would have been slow, for example, but 9 is perfect for such things.
It would be great to hear what people think should be the priorities, what raster items to add first (so people and system can cogitate on what's best to do next), then next steps and so on.