When using large contraptions that span multiple chunks.
I have a 4 chunk long Drill array with a gantry in the 5th cunks, in total 64+2ish blocks.

The chunk loader centers the chunk loading on the chunk containing the gantry itself.
this means 2 of the 5 total chunks end up being chunk loaded.

Not sure if its possible, but might suggest forcing multiple chunks and doing some math to keep 1+ chunks loaded outside of the contraption on all sides.
Thinking something like:
Num chunk loads in X: ceiling(( X Width + 32) / 48)
Num chunk loads in Z: ceiling(( Z Width + 32) / 48 )