I have added support to my SCDTools (http://sourceforge.net/p/scdtools/code/HEAD/tree/) to extract data from the GST file format (scdgstextract). The coolest features is that it makes composite images based on the VDP data. Here is a sample of the first level in hyperstone heist. If you examine the gif, it has 23 frames with unique frames for scroll low, scroll high, window low, window high, backdrop, and each sprite in use. My initial main goal of making the composite is to be able to see how the seperate sprites are used to make multiple sprite characters.
you can examine almost all this stuff in gens-rerecording by toggling layers.
also, you can see sprite decomposition in my mod: gens rerecording r57shell mod.
A little demonstration: https://www.youtube.com/watch?v=5la3tQe7B_0
Thanks for the tip about gens rerecording, didn't know about that feature and that is pretty cool.
My long term goal is to disassemble and port hyperstone heist to the SCD and add in additional content (borrowed from turtles in time and new stuff). Sometimes I get distracted with side projects though