thank you so much! I think I will continue trying this technique out but maybe for a different architecture. the game boy's limitations (mostly not having many registers, needing two registers to store an address, slow) make it kinda tricky - your compiler has to be pretty smart if you want decent code! I might try out a similar thing on x86_64 (or maybe ARM, for the GBA). much to do!
(love your site by the way! big fan!)