“We’ve almost got some of their telecommunications cracked; the front end even runs on a laptop!” The Mac that sunk a thousand ships could have been merely clunky product placement, not a bafflingly stupid tech-on-film moment.
“Senator Amidala is in a coma. Even if she recovers, she will never be the same and may not live long.” But no… George had to have his god-damned funeral scene, even if it demanded Simone Biles levels of mental gymnastics to save Carrie Fisher’s most emotionally resonant moment from ROTJ, as well as one of the more intriguing OT lore dumps.
Bonus points if a scene was scripted or filmed and got cut.
Using brainpower to power the matrix makes sense, but it sounded like OP was initially just saying for spare computing period, whether for the matrix or anything else even if it wasn’t related.
“Using their spare brainpower” sounds more like them using the remaining parts of someone’s brain that is not used for whatever they do use to run their consciousness within the Matrix.