In fact, I'm quite relaxed about extensions for homework.
Kid hasn't done it because they had a sports match/were at other parent's/something kicked off at home/they just forgot - 'ok, bring it tomorrow'.
Detention kicks in per school policy if they still don't. Which is a fair consequence.
Incidentally, my ds is super bright but dyspraxic & hopelessly disorganised. He attends the school where I teach.
The teachers who get the best out of him - as he will cheerfully admit - are the ones who say 'no homework Little Crow? Hand it in tomorrow or you're in detention'. He sorts it, or he does it in detention. Then it's over.
The ones who fluster about giving extra chances etc are the ones who cause him to get extra stressed, totally behind, & ostrich over the whole hot mess.
I've had to have it written into his IEP that he is sanctioned like everyone else. The result has been a huge improvement.
If he misses revision sessions at GCSE or beyond because he's not met deadlines elsewhere, then that is how it will be. I'm increasingly hopeful that we won't have this issue beyond his current year 8, because those clear boundaries & consequences are in place.
Of COURSE there is room for slack. One of my most conscientious Y10s was off before Easter - quite ill. I had to email his mum & suggest she banned him from opening Google Classroom for my subject - he needs to get well, not fanny about doing homework.
But generally there needs to be clear expectations. Vague requirements don't do students any favours.
Also - it's detention, not the pillory. A mild & appropriate consequence.