I'm working on a high-level extension library for the 7up chips right now... it will put liberis's sprite functionality on-par with HuC's. Going well so far... this is relatively easy stuff. The only challenge really is the bit-twiddling of word 3 in the SATB. At present, liberis only has low-level sprite functionality, so you'd have to manage the SATB directly, which means a lot of know-how about how the SATB works. This extension library removes those details, but still leaves all the low-level functionality exposed so no existing code is broken.