How to carve up ZX Basic into different ORG values

[RandomiserUsr]

You don't need to keep to the memory addresses I have indicated before.
You should prepare a memory map where you should place everything, first as a provisional map and then fit the pieces gradually, taking into account that in Boriel Basic it is very easy to change the compilation address (ORG).

First define the modules, for example:
- Main module
- Vars memory
- Game modules (dynamic loading)
- Sprites
- Tiles
- Music (IM2 player)?

Then place into memory, with a first approach:
$6000 - Main module
$7000 - Vars
$8000 - Game modules (dynamic loading)
$c000 - Sprites
$d000 - Tiles
$e000 - IM2 music player

Start to make modules and adjust the memory to fit the modules, for example:
$6000 - Main module
$7e00 - Vars
$8100 - Game modules (dynamic loading)
$c100 - Sprites
$d100 - Tiles
$e100 - IM2 music player

Hope it helps!

Thanks again - I will try this approach out (though it won't have any sprites or music, just text and graphics)