EXOS 2.1 doc also available, you can use it, EXOS 1.0 may contains obsolete information also.
I checked the codes, yes, a lot of memory, and a lot of CPU time can be saved by this blocky graphics setting, Endi mentioned a PC blocky game which resolution about 120 x 100 with 256 colour, unfortunately I do not remember to the name of the game, similar game could be realized with littlebit less resolution.