Yeah you are gettin' ahead of me -- exactly what I was planning! Great minds think alike!
I wanted one general routines cart, then a few carts as you describe. ;^)
This is the list I had so far for Optional Toy Box Jam Code:
-- color font print routines (with top/bottom colorizable borders&background, without borders but colorizable background, or just font with drop shadow), big print version of same
--print Pico font with outline
--simple collision
--simple colorizable windows
--starfield with depth and direction
-- ASC(same as ORD) and CHR ASCII number to character and back routines
--Particles
--Easing functions
--progress meter routine
--double-size sprite routine drawing
— screen shake
— printc
— distance between points (with safe SQRT)
—-trifill etc
— POKEd proportional font
-- > 10000 score meter
Let me know if you see basic things that would be helpful.....