Pixel gpt 4.2 is out with new custom any size pixel art model, make custom items any size between 6x6 to 92x92.
Use the filters strength to ensure the quality of generations, a rule of thumb is :
for 16px images for example :
use 10 strength for 16 px filter strength, anf you can use 0 to 5 strength for 32 filter strength and 0-2 strength using 64px filter strength.
for 24px images :
use 7-10 strength for 16px filter strength, 2-5 strength for 32px filter strength and 0 to 3 strength using 64px filter strength.
For 32px images :
use 0-5 strength for 16px filter strength, 7-10 strength for 32px filter strength and 0-5 strength for 64px filter strength.
etc, etc... I think you see the pattern there.
YOu can use style selector with this model ( CUSTOM ANY SIZE PIXEL )
Also full texture pack model V3 is out using different style, thow it is still not perfect from my point of view, v4 is in todo.